feat(oonirun): improve tests (#915)

See https://github.com/ooni/probe/issues/2184

While there, rename `runtimex.PanicIfFalse` to `runtimex.Assert` (it was about time...)

internal/cmd/miniooni/consent.go

@@ -17,7 +17,7 @@ func acquireUserConsent(miniooniDir string, currentOptions *Options) {
 	consentFile := path.Join(miniooniDir, "informed")
 	err := maybeWriteConsentFile(currentOptions.Yes, consentFile)
 	runtimex.PanicOnError(err, "cannot write informed consent file")
-	runtimex.PanicIfFalse(
+	runtimex.Assert(
 		regularFileExists(consentFile),
 		riskOfRunningOONI,
 	)

internal/cmd/miniooni/main.go

@@ -308,7 +308,7 @@ func mainSingleIteration(logger model.Logger, experimentName string, currentOpti
 	log.Infof("Current time: %s", time.Now().Format("2006-01-02 15:04:05 MST"))
 
 	homeDir := gethomedir(currentOptions.HomeDir)
-	runtimex.PanicIfFalse(homeDir != "", "home directory is empty")
+	runtimex.Assert(homeDir != "", "home directory is empty")
 	miniooniDir := path.Join(homeDir, ".miniooni")
 	err := os.MkdirAll(miniooniDir, 0700)
 	runtimex.PanicOnError(err, "cannot create $HOME/.miniooni directory")

internal/engine/mockable/mockable.go

@@ -11,6 +11,8 @@ import (
 )
 
 // Session allows to mock sessions.
+//
+// Deprecated: use ./internal/model/mocks.Session instead.
 type Session struct {
 	MockableTestHelpers              map[string][]model.OOAPIService
 	MockableHTTPClient               model.HTTPClient

internal/engine/saver.go

@@ -6,10 +6,8 @@ import (
 	"github.com/ooni/probe-cli/v3/internal/model"
 )
 
-// Saver saves a measurement on some persistent storage.
-type Saver interface {
-	SaveMeasurement(m *model.Measurement) error
-}
+// Saver is an alias for model.Saver.
+type Saver = model.Saver
 
 // SaverConfig is the configuration for creating a new Saver.
 type SaverConfig struct {

internal/engine/submitter.go

@@ -9,12 +9,8 @@ import (
 // TODO(bassosimone): maybe keep track of which measurements
 // could not be submitted by a specific submitter?
 
-// Submitter submits a measurement to the OONI collector.
-type Submitter interface {
-	// Submit submits the measurement and updates its
-	// report ID field in case of success.
-	Submit(ctx context.Context, m *model.Measurement) error
-}
+// Submitter is an alias for model.Submitter
+type Submitter = model.Submitter
 
 // SubmitterSession is the Submitter's view of the Session.
 type SubmitterSession interface {

internal/measurexlite/failure.go

@@ -27,7 +27,7 @@ func NewFailure(err error) *string {
 	if !errors.As(err, &errWrapper) {
 		err := netxlite.NewTopLevelGenericErrWrapper(err)
 		couldConvert := errors.As(err, &errWrapper)
-		runtimex.PanicIfFalse(couldConvert, "we should have an ErrWrapper here")
+		runtimex.Assert(couldConvert, "we should have an ErrWrapper here")
 	}
 	s := errWrapper.Failure
 	if s == "" {

internal/model/experiment.go

@@ -281,3 +281,25 @@ type ExperimentOptionInfo struct {
 	// Type contains the type.
 	Type string
 }
+
+// ExperimentInputLoader loads inputs from local or remote sources.
+type ExperimentInputLoader interface {
+	Load(ctx context.Context) ([]OOAPIURLInfo, error)
+}
+
+// Submitter submits a measurement to the OONI collector.
+type Submitter interface {
+	// Submit submits the measurement and updates its
+	// report ID field in case of success.
+	Submit(ctx context.Context, m *Measurement) error
+}
+
+// Saver saves a measurement on some persistent storage.
+type Saver interface {
+	SaveMeasurement(m *Measurement) error
+}
+
+// ExperimentInputProcessor processes inputs for an experiment.
+type ExperimentInputProcessor interface {
+	Run(ctx context.Context) error
+}

internal/model/mocks/experiment.go

@@ -0,0 +1,75 @@
+package mocks
+
+import (
+	"context"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+// Experiment mocks model.Experiment
+type Experiment struct {
+	MockKibiBytesReceived func() float64
+
+	MockKibiBytesSent func() float64
+
+	MockName func() string
+
+	MockGetSummaryKeys func(m *model.Measurement) (any, error)
+
+	MockReportID func() string
+
+	MockMeasureAsync func(ctx context.Context, input string) (<-chan *model.Measurement, error)
+
+	MockMeasureWithContext func(
+		ctx context.Context, input string) (measurement *model.Measurement, err error)
+
+	MockSaveMeasurement func(measurement *model.Measurement, filePath string) error
+
+	MockSubmitAndUpdateMeasurementContext func(
+		ctx context.Context, measurement *model.Measurement) error
+
+	MockOpenReportContext func(ctx context.Context) error
+}
+
+func (e *Experiment) KibiBytesReceived() float64 {
+	return e.MockKibiBytesReceived()
+}
+
+func (e *Experiment) KibiBytesSent() float64 {
+	return e.MockKibiBytesSent()
+}
+
+func (e *Experiment) Name() string {
+	return e.MockName()
+}
+
+func (e *Experiment) GetSummaryKeys(m *model.Measurement) (any, error) {
+	return e.MockGetSummaryKeys(m)
+}
+
+func (e *Experiment) ReportID() string {
+	return e.MockReportID()
+}
+
+func (e *Experiment) MeasureAsync(
+	ctx context.Context, input string) (<-chan *model.Measurement, error) {
+	return e.MockMeasureAsync(ctx, input)
+}
+
+func (e *Experiment) MeasureWithContext(
+	ctx context.Context, input string) (measurement *model.Measurement, err error) {
+	return e.MockMeasureWithContext(ctx, input)
+}
+
+func (e *Experiment) SaveMeasurement(measurement *model.Measurement, filePath string) error {
+	return e.MockSaveMeasurement(measurement, filePath)
+}
+
+func (e *Experiment) SubmitAndUpdateMeasurementContext(
+	ctx context.Context, measurement *model.Measurement) error {
+	return e.MockSubmitAndUpdateMeasurementContext(ctx, measurement)
+}
+
+func (e *Experiment) OpenReportContext(ctx context.Context) error {
+	return e.MockOpenReportContext(ctx)
+}

internal/model/mocks/experiment_test.go

@@ -0,0 +1,146 @@
+package mocks
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+func TestExperiment(t *testing.T) {
+	t.Run("KibiBytesReceived", func(t *testing.T) {
+		expected := 1.0
+		e := &Experiment{
+			MockKibiBytesReceived: func() float64 {
+				return expected
+			},
+		}
+		if e.KibiBytesReceived() != expected {
+			t.Fatal("unexpected result")
+		}
+	})
+
+	t.Run("KibiBytesSent", func(t *testing.T) {
+		expected := 1.0
+		e := &Experiment{
+			MockKibiBytesSent: func() float64 {
+				return expected
+			},
+		}
+		if e.KibiBytesSent() != expected {
+			t.Fatal("unexpected result")
+		}
+	})
+
+	t.Run("Name", func(t *testing.T) {
+		expected := "antani"
+		e := &Experiment{
+			MockName: func() string {
+				return expected
+			},
+		}
+		if e.Name() != expected {
+			t.Fatal("unexpected result")
+		}
+	})
+
+	t.Run("GetSummaryKeys", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		e := &Experiment{
+			MockGetSummaryKeys: func(m *model.Measurement) (any, error) {
+				return nil, expected
+			},
+		}
+		out, err := e.GetSummaryKeys(&model.Measurement{})
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if out != nil {
+			t.Fatal("invalid out")
+		}
+	})
+
+	t.Run("ReportID", func(t *testing.T) {
+		expect := "xyz"
+		e := &Experiment{
+			MockReportID: func() string {
+				return expect
+			},
+		}
+		if e.ReportID() != expect {
+			t.Fatal("invalid value")
+		}
+	})
+
+	t.Run("MeasureAsync", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		e := &Experiment{
+			MockMeasureAsync: func(ctx context.Context, input string) (<-chan *model.Measurement, error) {
+				return nil, expected
+			},
+		}
+		out, err := e.MeasureAsync(context.Background(), "xo")
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if out != nil {
+			t.Fatal("expected nil")
+		}
+	})
+
+	t.Run("MeasureWithContext", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		e := &Experiment{
+			MockMeasureWithContext: func(ctx context.Context, input string) (measurement *model.Measurement, err error) {
+				return nil, expected
+			},
+		}
+		out, err := e.MeasureWithContext(context.Background(), "xo")
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if out != nil {
+			t.Fatal("expected nil")
+		}
+	})
+
+	t.Run("SaveMeasurement", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		e := &Experiment{
+			MockSaveMeasurement: func(measurement *model.Measurement, filePath string) error {
+				return expected
+			},
+		}
+		err := e.SaveMeasurement(&model.Measurement{}, "x")
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("SubmitAndUpdateMeasurementContext", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		e := &Experiment{
+			MockSubmitAndUpdateMeasurementContext: func(ctx context.Context, measurement *model.Measurement) error {
+				return expected
+			},
+		}
+		err := e.SubmitAndUpdateMeasurementContext(context.Background(), &model.Measurement{})
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("OpenReportContext", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		e := &Experiment{
+			MockOpenReportContext: func(ctx context.Context) error {
+				return expected
+			},
+		}
+		err := e.OpenReportContext(context.Background())
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+}

internal/model/mocks/experimentbuilder.go

@@ -0,0 +1,48 @@
+package mocks
+
+import "github.com/ooni/probe-cli/v3/internal/model"
+
+// ExperimentBuilder mocks model.ExperimentBuilder.
+type ExperimentBuilder struct {
+	MockInterruptible func() bool
+
+	MockInputPolicy func() model.InputPolicy
+
+	MockOptions func() (map[string]model.ExperimentOptionInfo, error)
+
+	MockSetOptionAny func(key string, value any) error
+
+	MockSetOptionsAny func(options map[string]any) error
+
+	MockSetCallbacks func(callbacks model.ExperimentCallbacks)
+
+	MockNewExperiment func() model.Experiment
+}
+
+func (eb *ExperimentBuilder) Interruptible() bool {
+	return eb.MockInterruptible()
+}
+
+func (eb *ExperimentBuilder) InputPolicy() model.InputPolicy {
+	return eb.MockInputPolicy()
+}
+
+func (eb *ExperimentBuilder) Options() (map[string]model.ExperimentOptionInfo, error) {
+	return eb.MockOptions()
+}
+
+func (eb *ExperimentBuilder) SetOptionAny(key string, value any) error {
+	return eb.MockSetOptionAny(key, value)
+}
+
+func (eb *ExperimentBuilder) SetOptionsAny(options map[string]any) error {
+	return eb.MockSetOptionsAny(options)
+}
+
+func (eb *ExperimentBuilder) SetCallbacks(callbacks model.ExperimentCallbacks) {
+	eb.MockSetCallbacks(callbacks)
+}
+
+func (eb *ExperimentBuilder) NewExperiment() model.Experiment {
+	return eb.MockNewExperiment()
+}

internal/model/mocks/experimentbuilder_test.go

@@ -0,0 +1,99 @@
+package mocks
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+func TestExperimentBuilder(t *testing.T) {
+	t.Run("Interruptible", func(t *testing.T) {
+		eb := &ExperimentBuilder{
+			MockInterruptible: func() bool {
+				return true
+			},
+		}
+		if !eb.Interruptible() {
+			t.Fatal("unexpected value")
+		}
+	})
+
+	t.Run("InputPolicy", func(t *testing.T) {
+		eb := &ExperimentBuilder{
+			MockInputPolicy: func() model.InputPolicy {
+				return model.InputOrQueryBackend
+			},
+		}
+		if eb.InputPolicy() != model.InputOrQueryBackend {
+			t.Fatal("unexpected value")
+		}
+	})
+
+	t.Run("Options", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		eb := &ExperimentBuilder{
+			MockOptions: func() (map[string]model.ExperimentOptionInfo, error) {
+				return nil, expected
+			},
+		}
+		out, err := eb.Options()
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected value")
+		}
+		if len(out) > 0 {
+			t.Fatal("unexpected value")
+		}
+	})
+
+	t.Run("SetOptionAny", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		eb := &ExperimentBuilder{
+			MockSetOptionAny: func(key string, value any) error {
+				return expected
+			},
+		}
+		err := eb.SetOptionAny("antani", 1245678)
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected value")
+		}
+	})
+
+	t.Run("SetOptionsAny", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		eb := &ExperimentBuilder{
+			MockSetOptionsAny: func(options map[string]any) error {
+				return expected
+			},
+		}
+		err := eb.SetOptionsAny(make(map[string]any))
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected value")
+		}
+	})
+
+	t.Run("SetCallbacks", func(t *testing.T) {
+		var called bool
+		eb := &ExperimentBuilder{
+			MockSetCallbacks: func(callbacks model.ExperimentCallbacks) {
+				called = true
+			},
+		}
+		eb.SetCallbacks(model.NewPrinterCallbacks(model.DiscardLogger))
+		if !called {
+			t.Fatal("not called")
+		}
+	})
+
+	t.Run("NewExperiment", func(t *testing.T) {
+		exp := &Experiment{}
+		eb := &ExperimentBuilder{
+			MockNewExperiment: func() model.Experiment {
+				return exp
+			},
+		}
+		if out := eb.NewExperiment(); out != exp {
+			t.Fatal("invalid result")
+		}
+	})
+}

internal/model/mocks/experimentinputloader.go

@@ -0,0 +1,19 @@
+package mocks
+
+import (
+	"context"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+// ExperimentInputLoader mocks model.ExperimentInputLoader
+type ExperimentInputLoader struct {
+	MockLoad func(ctx context.Context) ([]model.OOAPIURLInfo, error)
+}
+
+var _ model.ExperimentInputLoader = &ExperimentInputLoader{}
+
+// Load calls MockLoad
+func (eil *ExperimentInputLoader) Load(ctx context.Context) ([]model.OOAPIURLInfo, error) {
+	return eil.MockLoad(ctx)
+}

internal/model/mocks/experimentinputloader_test.go

@@ -0,0 +1,27 @@
+package mocks
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+func TestExperimentInputLoader(t *testing.T) {
+	t.Run("Load", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		eil := &ExperimentInputLoader{
+			MockLoad: func(ctx context.Context) ([]model.OOAPIURLInfo, error) {
+				return nil, expected
+			},
+		}
+		out, err := eil.Load(context.Background())
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if len(out) > 0 {
+			t.Fatal("unexpected length")
+		}
+	})
+}

internal/model/mocks/experimentinputprocessor.go

@@ -0,0 +1,12 @@
+package mocks
+
+import "context"
+
+// ExperimentInputProcessor processes inputs running the given experiment.
+type ExperimentInputProcessor struct {
+	MockRun func(ctx context.Context) error
+}
+
+func (eip *ExperimentInputProcessor) Run(ctx context.Context) error {
+	return eip.MockRun(ctx)
+}

internal/model/mocks/experimentinputprocessor_test.go

@@ -0,0 +1,22 @@
+package mocks
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+func TestExperimentInputProcessor(t *testing.T) {
+	t.Run("Run", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		eip := &ExperimentInputProcessor{
+			MockRun: func(ctx context.Context) error {
+				return expected
+			},
+		}
+		err := eip.Run(context.Background())
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected result")
+		}
+	})
+}

internal/model/mocks/saver.go

@@ -0,0 +1,12 @@
+package mocks
+
+import "github.com/ooni/probe-cli/v3/internal/model"
+
+// Saver saves a measurement on some persistent storage.
+type Saver struct {
+	MockSaveMeasurement func(m *model.Measurement) error
+}
+
+func (s *Saver) SaveMeasurement(m *model.Measurement) error {
+	return s.MockSaveMeasurement(m)
+}

internal/model/mocks/saver_test.go

@@ -0,0 +1,23 @@
+package mocks
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+func TestSaver(t *testing.T) {
+	t.Run("SaveMeasurement", func(t *testing.T) {
+		expected := errors.New("mocked error")
+		s := &Saver{
+			MockSaveMeasurement: func(m *model.Measurement) error {
+				return expected
+			},
+		}
+		err := s.SaveMeasurement(&model.Measurement{})
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+}

internal/model/mocks/session.go

@@ -0,0 +1,161 @@
+package mocks
+
+import (
+	"context"
+	"net/url"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+// Session allows to mock sessions.
+type Session struct {
+	MockGetTestHelpersByName func(name string) ([]model.OOAPIService, bool)
+
+	MockDefaultHTTPClient func() model.HTTPClient
+
+	MockFetchPsiphonConfig func(ctx context.Context) ([]byte, error)
+
+	MockFetchTorTargets func(
+		ctx context.Context, cc string) (map[string]model.OOAPITorTarget, error)
+
+	MockFetchURLList func(
+		ctx context.Context, config model.OOAPIURLListConfig) ([]model.OOAPIURLInfo, error)
+
+	MockKeyValueStore func() model.KeyValueStore
+
+	MockLogger func() model.Logger
+
+	MockMaybeResolverIP func() string
+
+	MockProbeASNString func() string
+
+	MockProbeCC func() string
+
+	MockProbeIP func() string
+
+	MockProbeNetworkName func() string
+
+	MockProxyURL func() *url.URL
+
+	MockResolverIP func() string
+
+	MockSoftwareName func() string
+
+	MockSoftwareVersion func() string
+
+	MockTempDir func() string
+
+	MockTorArgs func() []string
+
+	MockTorBinary func() string
+
+	MockTunnelDir func() string
+
+	MockUserAgent func() string
+
+	MockNewExperimentBuilder func(name string) (model.ExperimentBuilder, error)
+
+	MockNewSubmitter func(ctx context.Context) (model.Submitter, error)
+
+	MockCheckIn func(ctx context.Context,
+		config *model.OOAPICheckInConfig) (*model.OOAPICheckInInfo, error)
+}
+
+func (sess *Session) GetTestHelpersByName(name string) ([]model.OOAPIService, bool) {
+	return sess.MockGetTestHelpersByName(name)
+}
+
+func (sess *Session) DefaultHTTPClient() model.HTTPClient {
+	return sess.MockDefaultHTTPClient()
+}
+
+func (sess *Session) FetchPsiphonConfig(ctx context.Context) ([]byte, error) {
+	return sess.MockFetchPsiphonConfig(ctx)
+}
+
+func (sess *Session) FetchTorTargets(
+	ctx context.Context, cc string) (map[string]model.OOAPITorTarget, error) {
+	return sess.MockFetchTorTargets(ctx, cc)
+}
+
+func (sess *Session) FetchURLList(
+	ctx context.Context, config model.OOAPIURLListConfig) ([]model.OOAPIURLInfo, error) {
+	return sess.MockFetchURLList(ctx, config)
+}
+
+func (sess *Session) KeyValueStore() model.KeyValueStore {
+	return sess.MockKeyValueStore()
+}
+
+func (sess *Session) Logger() model.Logger {
+	return sess.MockLogger()
+}
+
+func (sess *Session) MaybeResolverIP() string {
+	return sess.MockMaybeResolverIP()
+}
+
+func (sess *Session) ProbeASNString() string {
+	return sess.MockProbeASNString()
+}
+
+func (sess *Session) ProbeCC() string {
+	return sess.MockProbeCC()
+}
+
+func (sess *Session) ProbeIP() string {
+	return sess.MockProbeIP()
+}
+
+func (sess *Session) ProbeNetworkName() string {
+	return sess.MockProbeNetworkName()
+}
+
+func (sess *Session) ProxyURL() *url.URL {
+	return sess.MockProxyURL()
+}
+
+func (sess *Session) ResolverIP() string {
+	return sess.MockResolverIP()
+}
+
+func (sess *Session) SoftwareName() string {
+	return sess.MockSoftwareName()
+}
+
+func (sess *Session) SoftwareVersion() string {
+	return sess.MockSoftwareVersion()
+}
+
+func (sess *Session) TempDir() string {
+	return sess.MockTempDir()
+}
+
+func (sess *Session) TorArgs() []string {
+	return sess.MockTorArgs()
+}
+
+func (sess *Session) TorBinary() string {
+	return sess.MockTorBinary()
+}
+
+func (sess *Session) TunnelDir() string {
+	return sess.MockTunnelDir()
+}
+
+func (sess *Session) UserAgent() string {
+	return sess.MockUserAgent()
+}
+
+func (sess *Session) NewExperimentBuilder(name string) (model.ExperimentBuilder, error) {
+	return sess.MockNewExperimentBuilder(name)
+}
+
+func (sess *Session) NewSubmitter(ctx context.Context) (model.Submitter, error) {
+	return sess.MockNewSubmitter(ctx)
+}
+
+func (sess *Session) CheckIn(ctx context.Context,
+	config *model.OOAPICheckInConfig) (*model.OOAPICheckInInfo, error) {
+	return sess.MockCheckIn(ctx, config)
+}

internal/model/mocks/session_test.go

@@ -0,0 +1,357 @@
+package mocks
+
+import (
+	"context"
+	"errors"
+	"net/url"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/ooni/probe-cli/v3/internal/model"
+	"github.com/ooni/probe-cli/v3/internal/runtimex"
+	"github.com/ooni/probe-cli/v3/internal/testingx"
+)
+
+func TestSession(t *testing.T) {
+	t.Run("GetTestHelpersByName", func(t *testing.T) {
+		var expect []model.OOAPIService
+		ff := &testingx.FakeFiller{}
+		ff.Fill(&expect)
+		runtimex.Assert(len(expect) > 0, "expected non-empty array")
+		s := &Session{
+			MockGetTestHelpersByName: func(name string) ([]model.OOAPIService, bool) {
+				return expect, len(expect) > 0
+			},
+		}
+		out, good := s.GetTestHelpersByName("xx")
+		if !good {
+			t.Fatal("not good")
+		}
+		if diff := cmp.Diff(expect, out); diff != "" {
+			t.Fatal(diff)
+		}
+	})
+
+	t.Run("DefaultHTTPClient", func(t *testing.T) {
+		expected := &HTTPClient{}
+		s := &Session{
+			MockDefaultHTTPClient: func() model.HTTPClient {
+				return expected
+			},
+		}
+		out := s.DefaultHTTPClient()
+		if expected != out {
+			t.Fatal("unexpected result")
+		}
+	})
+
+	t.Run("FetchPsiphonConfig", func(t *testing.T) {
+		var expected []byte
+		ff := &testingx.FakeFiller{}
+		ff.Fill(&expected)
+		runtimex.Assert(len(expected) > 0, "expected nonempty list")
+		s := &Session{
+			MockFetchPsiphonConfig: func(ctx context.Context) ([]byte, error) {
+				return expected, nil
+			},
+		}
+		out, err := s.FetchPsiphonConfig(context.Background())
+		if err != nil {
+			t.Fatal(err)
+		}
+		if diff := cmp.Diff(expected, out); diff != "" {
+			t.Fatal(diff)
+		}
+	})
+
+	t.Run("FetchTorTargets", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		s := &Session{
+			MockFetchTorTargets: func(ctx context.Context, cc string) (map[string]model.OOAPITorTarget, error) {
+				return nil, expected
+			},
+		}
+		out, err := s.FetchTorTargets(context.Background(), "IT")
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if len(out) > 0 {
+			t.Fatal("expected empty out")
+		}
+	})
+
+	t.Run("FetchURLList", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		s := &Session{
+			MockFetchURLList: func(ctx context.Context, config model.OOAPIURLListConfig) ([]model.OOAPIURLInfo, error) {
+				return nil, expected
+			},
+		}
+		out, err := s.FetchURLList(context.Background(), model.OOAPIURLListConfig{})
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err", err)
+		}
+		if len(out) > 0 {
+			t.Fatal("expected empty out")
+		}
+	})
+
+	t.Run("KeyValueStore", func(t *testing.T) {
+		expect := &KeyValueStore{}
+		s := &Session{
+			MockKeyValueStore: func() model.KeyValueStore {
+				return expect
+			},
+		}
+		out := s.KeyValueStore()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("Logger", func(t *testing.T) {
+		expect := &Logger{}
+		s := &Session{
+			MockLogger: func() model.Logger {
+				return expect
+			},
+		}
+		out := s.Logger()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("MaybeResolverIP", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockMaybeResolverIP: func() string {
+				return expect
+			},
+		}
+		out := s.MaybeResolverIP()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("ProbeASNString", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockProbeASNString: func() string {
+				return expect
+			},
+		}
+		out := s.ProbeASNString()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("ProbeCC", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockProbeCC: func() string {
+				return expect
+			},
+		}
+		out := s.ProbeCC()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("ProbeIP", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockProbeIP: func() string {
+				return expect
+			},
+		}
+		out := s.ProbeIP()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("ProbeNetworkName", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockProbeNetworkName: func() string {
+				return expect
+			},
+		}
+		out := s.ProbeNetworkName()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("ProxyURL", func(t *testing.T) {
+		expect := &url.URL{Scheme: "xx"}
+		s := &Session{
+			MockProxyURL: func() *url.URL {
+				return expect
+			},
+		}
+		out := s.ProxyURL()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("ResolverIP", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockResolverIP: func() string {
+				return expect
+			},
+		}
+		out := s.ResolverIP()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("SoftwareName", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockSoftwareName: func() string {
+				return expect
+			},
+		}
+		out := s.SoftwareName()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("SoftwareVersion", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockSoftwareVersion: func() string {
+				return expect
+			},
+		}
+		out := s.SoftwareVersion()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("TempDir", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockTempDir: func() string {
+				return expect
+			},
+		}
+		out := s.TempDir()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("TorArgs", func(t *testing.T) {
+		var expect []string
+		ff := &testingx.FakeFiller{}
+		ff.Fill(&expect)
+		runtimex.Assert(len(expect) > 0, "expected non empty slice")
+		s := &Session{
+			MockTorArgs: func() []string {
+				return expect
+			},
+		}
+		out := s.TorArgs()
+		if diff := cmp.Diff(expect, out); diff != "" {
+			t.Fatal(diff)
+		}
+	})
+
+	t.Run("TorBinary", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockTorBinary: func() string {
+				return expect
+			},
+		}
+		out := s.TorBinary()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("TunnelDir", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockTunnelDir: func() string {
+				return expect
+			},
+		}
+		out := s.TunnelDir()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("UserAgent", func(t *testing.T) {
+		expect := "xx"
+		s := &Session{
+			MockUserAgent: func() string {
+				return expect
+			},
+		}
+		out := s.UserAgent()
+		if out != expect {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("NewExperimentBuilder", func(t *testing.T) {
+		eb := &ExperimentBuilder{}
+		s := &Session{
+			MockNewExperimentBuilder: func(name string) (model.ExperimentBuilder, error) {
+				return eb, nil
+			},
+		}
+		out, err := s.NewExperimentBuilder("x")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if out != eb {
+			t.Fatal("invalid output")
+		}
+	})
+
+	t.Run("NewSubmitter", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		s := &Session{
+			MockNewSubmitter: func(ctx context.Context) (model.Submitter, error) {
+				return nil, expected
+			},
+		}
+		out, err := s.NewSubmitter(context.Background())
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err")
+		}
+		if out != nil {
+			t.Fatal("unexpected out")
+		}
+	})
+
+	t.Run("CheckIn", func(t *testing.T) {
+		expected := errors.New("mocked err")
+		s := &Session{
+			MockCheckIn: func(ctx context.Context, config *model.OOAPICheckInConfig) (*model.OOAPICheckInInfo, error) {
+				return nil, expected
+			},
+		}
+		out, err := s.CheckIn(context.Background(), &model.OOAPICheckInConfig{})
+		if !errors.Is(err, expected) {
+			t.Fatal("unexpected err")
+		}
+		if out != nil {
+			t.Fatal("unexpected out")
+		}
+	})
+}

internal/model/mocks/submitter.go

@@ -0,0 +1,17 @@
+package mocks
+
+import (
+	"context"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+// Submitter mocks model.Submitter.
+type Submitter struct {
+	MockSubmit func(ctx context.Context, m *model.Measurement) error
+}
+
+// Submit calls MockSubmit
+func (s *Submitter) Submit(ctx context.Context, m *model.Measurement) error {
+	return s.MockSubmit(ctx, m)
+}

internal/model/mocks/submitter_test.go

@@ -0,0 +1,24 @@
+package mocks
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+func TestSubmitter(t *testing.T) {
+	t.Run("Submit", func(t *testing.T) {
+		expect := errors.New("mocked error")
+		s := &Submitter{
+			MockSubmit: func(ctx context.Context, m *model.Measurement) error {
+				return expect
+			},
+		}
+		err := s.Submit(context.Background(), &model.Measurement{})
+		if !errors.Is(err, expect) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+}

internal/netxlite/dnsdecoder_test.go

@@ -613,9 +613,9 @@ func dnsGenLookupHostReplySuccess(rawQuery []byte, cname *dnsCNAMEAnswer, ips ..
 	query := new(dns.Msg)
 	err := query.Unpack(rawQuery)
 	runtimex.PanicOnError(err, "query.Unpack failed")
-	runtimex.PanicIfFalse(len(query.Question) == 1, "more than one question")
+	runtimex.Assert(len(query.Question) == 1, "more than one question")
 	question := query.Question[0]
-	runtimex.PanicIfFalse(
+	runtimex.Assert(
 		question.Qtype == dns.TypeA || question.Qtype == dns.TypeAAAA,
 		"invalid query type (expected A or AAAA)",
 	)
@@ -669,9 +669,9 @@ func dnsGenHTTPSReplySuccess(rawQuery []byte, alpns, ipv4s, ipv6s []string) []by
 	query := new(dns.Msg)
 	err := query.Unpack(rawQuery)
 	runtimex.PanicOnError(err, "query.Unpack failed")
-	runtimex.PanicIfFalse(len(query.Question) == 1, "expected just a single question")
+	runtimex.Assert(len(query.Question) == 1, "expected just a single question")
 	question := query.Question[0]
-	runtimex.PanicIfFalse(question.Qtype == dns.TypeHTTPS, "expected HTTPS query")
+	runtimex.Assert(question.Qtype == dns.TypeHTTPS, "expected HTTPS query")
 	reply := new(dns.Msg)
 	reply.Compress = true
 	reply.MsgHdr.RecursionAvailable = true
@@ -716,9 +716,9 @@ func dnsGenNSReplySuccess(rawQuery []byte, names ...string) []byte {
 	query := new(dns.Msg)
 	err := query.Unpack(rawQuery)
 	runtimex.PanicOnError(err, "query.Unpack failed")
-	runtimex.PanicIfFalse(len(query.Question) == 1, "more than one question")
+	runtimex.Assert(len(query.Question) == 1, "more than one question")
 	question := query.Question[0]
-	runtimex.PanicIfFalse(question.Qtype == dns.TypeNS, "expected NS query")
+	runtimex.Assert(question.Qtype == dns.TypeNS, "expected NS query")
 	reply := new(dns.Msg)
 	reply.Compress = true
 	reply.MsgHdr.RecursionAvailable = true

internal/netxlite/tls.go

@@ -104,7 +104,7 @@ func NewDefaultCertPool() *x509.CertPool {
 	// Assumption: AppendCertsFromPEM cannot fail because we
 	// have a test in certify_test.go that guarantees that
 	ok := pool.AppendCertsFromPEM([]byte(pemcerts))
-	runtimex.PanicIfFalse(ok, "pool.AppendCertsFromPEM failed")
+	runtimex.Assert(ok, "pool.AppendCertsFromPEM failed")
 	return pool
 }
 

internal/oonirun/experiment.go

@@ -11,11 +11,15 @@ import (
 	"strings"
 	"time"
 
+	"github.com/ooni/probe-cli/v3/internal/atomicx"
 	"github.com/ooni/probe-cli/v3/internal/engine"
 	"github.com/ooni/probe-cli/v3/internal/humanize"
 	"github.com/ooni/probe-cli/v3/internal/model"
 )
 
+// experimentShuffledInputs counts how many times we shuffled inputs
+var experimentShuffledInputs = &atomicx.Int64{}
+
 // Experiment describes an experiment to run. You MUST fill all the fields that
 // are marked as MANDATORY, otherwise Experiment.Run will cause panics.
 type Experiment struct {
@@ -52,6 +56,22 @@ type Experiment struct {
 
 	// Session is the MANDATORY session.
 	Session Session
+
+	// newExperimentBuilderFn is OPTIONAL and used for testing.
+	newExperimentBuilderFn func(experimentName string) (model.ExperimentBuilder, error)
+
+	// newInputLoaderFn is OPTIONAL and used for testing.
+	newInputLoaderFn func(inputPolicy model.InputPolicy) inputLoader
+
+	// newSubmitterFn is OPTIONAL and used for testing.
+	newSubmitterFn func(ctx context.Context) (engine.Submitter, error)
+
+	// newSaverFn is OPTIONAL and used for testing.
+	newSaverFn func(experiment model.Experiment) (engine.Saver, error)
+
+	// newInputProcessorFn is OPTIONAL and used for testing.
+	newInputProcessorFn func(experiment model.Experiment, inputList []model.OOAPIURLInfo,
+		saver engine.Saver, submitter engine.Submitter) inputProcessor
 }
 
 // Run runs the given experiment.
@@ -76,6 +96,7 @@ func (ed *Experiment) Run(ctx context.Context) error {
 		rnd.Shuffle(len(inputList), func(i, j int) {
 			inputList[i], inputList[j] = inputList[j], inputList[i]
 		})
+		experimentShuffledInputs.Add(1)
 	}
 
 	// 4. configure experiment's options
@@ -112,14 +133,15 @@ func (ed *Experiment) Run(ctx context.Context) error {
 	return inputProcessor.Run(ctx)
 }
 
-// inputProcessor processes inputs running the given experiment.
-type inputProcessor interface {
-	Run(ctx context.Context) error
-}
+// inputProcessor is an alias for model.ExperimentInputProcessor
+type inputProcessor = model.ExperimentInputProcessor
 
 // newInputProcessor creates a new inputProcessor instance.
 func (ed *Experiment) newInputProcessor(experiment model.Experiment,
 	inputList []model.OOAPIURLInfo, saver engine.Saver, submitter engine.Submitter) inputProcessor {
+	if ed.newInputProcessorFn != nil {
+		return ed.newInputProcessorFn(experiment, inputList, saver, submitter)
+	}
 	return &engine.InputProcessor{
 		Annotations: ed.Annotations,
 		Experiment: &experimentWrapper{
@@ -140,6 +162,9 @@ func (ed *Experiment) newInputProcessor(experiment model.Experiment,
 
 // newSaver creates a new engine.Saver instance.
 func (ed *Experiment) newSaver(experiment model.Experiment) (engine.Saver, error) {
+	if ed.newSaverFn != nil {
+		return ed.newSaverFn(experiment)
+	}
 	return engine.NewSaver(engine.SaverConfig{
 		Enabled:    !ed.NoJSON,
 		Experiment: experiment,
@@ -150,6 +175,9 @@ func (ed *Experiment) newSaver(experiment model.Experiment) (engine.Saver, error
 
 // newSubmitter creates a new engine.Submitter instance.
 func (ed *Experiment) newSubmitter(ctx context.Context) (engine.Submitter, error) {
+	if ed.newSubmitterFn != nil {
+		return ed.newSubmitterFn(ctx)
+	}
 	return engine.NewSubmitter(ctx, engine.SubmitterConfig{
 		Enabled: !ed.NoCollector,
 		Session: ed.Session,
@@ -159,16 +187,20 @@ func (ed *Experiment) newSubmitter(ctx context.Context) (engine.Submitter, error
 
 // newExperimentBuilder creates a new engine.ExperimentBuilder for the given experimentName.
 func (ed *Experiment) newExperimentBuilder(experimentName string) (model.ExperimentBuilder, error) {
+	if ed.newExperimentBuilderFn != nil {
+		return ed.newExperimentBuilderFn(experimentName)
+	}
 	return ed.Session.NewExperimentBuilder(ed.Name)
 }
 
-// inputLoader loads inputs from local or remote sources.
-type inputLoader interface {
-	Load(ctx context.Context) ([]model.OOAPIURLInfo, error)
-}
+// inputLoader is an alias for model.ExperimentInputLoader
+type inputLoader = model.ExperimentInputLoader
 
 // newInputLoader creates a new inputLoader.
 func (ed *Experiment) newInputLoader(inputPolicy model.InputPolicy) inputLoader {
+	if ed.newInputLoaderFn != nil {
+		return ed.newInputLoaderFn(inputPolicy)
+	}
 	return &engine.InputLoader{
 		CheckInConfig: &model.OOAPICheckInConfig{
 			RunType:  model.RunTypeManual,

internal/oonirun/experiment_test.go

@@ -2,42 +2,24 @@ package oonirun
 
 import (
 	"context"
-	"os"
+	"errors"
 	"reflect"
 	"sort"
 	"testing"
 	"time"
 
 	"github.com/ooni/probe-cli/v3/internal/engine"
-	"github.com/ooni/probe-cli/v3/internal/kvstore"
 	"github.com/ooni/probe-cli/v3/internal/model"
-	"github.com/ooni/probe-cli/v3/internal/version"
+	"github.com/ooni/probe-cli/v3/internal/model/mocks"
+	"github.com/ooni/probe-cli/v3/internal/testingx"
 )
 
-// TODO(bassosimone): it would be cool to write unit tests. However, to do that
-// we need to ~redesign the engine package for unit-testability.
-
-func newSession(ctx context.Context, t *testing.T) *engine.Session {
-	config := engine.SessionConfig{
-		AvailableProbeServices: []model.OOAPIService{},
-		KVStore:                &kvstore.Memory{},
-		Logger:                 model.DiscardLogger,
-		ProxyURL:               nil,
-		SoftwareName:           "miniooni",
-		SoftwareVersion:        version.Version,
-		TempDir:                os.TempDir(),
-		TorArgs:                []string{},
-		TorBinary:              "",
-		TunnelDir:              "",
-	}
-	sess, err := engine.NewSession(ctx, config)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return sess
-}
-
-func TestExperimentRunWithExample(t *testing.T) {
+func TestExperimentRunWithFailureToSubmitAndShuffle(t *testing.T) {
+	shuffledInputsPrev := experimentShuffledInputs.Load()
+	var calledSetOptionsAny int
+	var failedToSubmit int
+	var calledKibiBytesReceived int
+	var calledKibiBytesSent int
 	ctx := context.Background()
 	desc := &Experiment{
 		Annotations: map[string]string{
@@ -46,19 +28,89 @@ func TestExperimentRunWithExample(t *testing.T) {
 		ExtraOptions: map[string]any{
 			"SleepTime": int64(10 * time.Millisecond),
 		},
-		Inputs:         []string{},
+		Inputs: []string{
+			"a", "b", "c",
+		},
 		InputFilePaths: []string{},
 		MaxRuntime:     0,
 		Name:           "example",
 		NoCollector:    true,
 		NoJSON:         true,
-		Random:         false,
+		Random:         true, // to test randomness
 		ReportFile:     "",
-		Session:        newSession(ctx, t),
+		Session: &mocks.Session{
+			MockNewExperimentBuilder: func(name string) (model.ExperimentBuilder, error) {
+				eb := &mocks.ExperimentBuilder{
+					MockInputPolicy: func() model.InputPolicy {
+						return model.InputOptional
+					},
+					MockSetOptionsAny: func(options map[string]any) error {
+						calledSetOptionsAny++
+						return nil
+					},
+					MockNewExperiment: func() model.Experiment {
+						exp := &mocks.Experiment{
+							MockMeasureAsync: func(ctx context.Context, input string) (<-chan *model.Measurement, error) {
+								out := make(chan *model.Measurement)
+								go func() {
+									defer close(out)
+									ff := &testingx.FakeFiller{}
+									var meas model.Measurement
+									ff.Fill(&meas)
+									out <- &meas
+								}()
+								return out, nil
+							},
+							MockKibiBytesReceived: func() float64 {
+								calledKibiBytesReceived++
+								return 1.453
+							},
+							MockKibiBytesSent: func() float64 {
+								calledKibiBytesSent++
+								return 1.648
+							},
+						}
+						return exp
+					},
+				}
+				return eb, nil
+			},
+			MockLogger: func() model.Logger {
+				return model.DiscardLogger
+			},
+		},
+		newExperimentBuilderFn: nil,
+		newInputLoaderFn:       nil,
+		newSubmitterFn: func(ctx context.Context) (engine.Submitter, error) {
+			subm := &mocks.Submitter{
+				MockSubmit: func(ctx context.Context, m *model.Measurement) error {
+					failedToSubmit++
+					return errors.New("mocked error")
+				},
+			}
+			return subm, nil
+		},
+		newSaverFn:          nil,
+		newInputProcessorFn: nil,
 	}
 	if err := desc.Run(ctx); err != nil {
 		t.Fatal(err)
 	}
+	if failedToSubmit < 1 {
+		t.Fatal("expected to see failure to submit")
+	}
+	if experimentShuffledInputs.Load() != shuffledInputsPrev+1 {
+		t.Fatal("did not shuffle inputs")
+	}
+	if calledSetOptionsAny < 1 {
+		t.Fatal("should have called SetOptionsAny")
+	}
+	if calledKibiBytesReceived < 1 {
+		t.Fatal("did not call KibiBytesReceived")
+	}
+	if calledKibiBytesSent < 1 {
+		t.Fatal("did not call KibiBytesSent")
+	}
 }
 
 func Test_experimentOptionsToStringList(t *testing.T) {
@@ -102,3 +154,257 @@ func Test_experimentOptionsToStringList(t *testing.T) {
 		})
 	}
 }
+
+func TestExperimentRun(t *testing.T) {
+	errMocked := errors.New("mocked error")
+	type fields struct {
+		Annotations            map[string]string
+		ExtraOptions           map[string]any
+		Inputs                 []string
+		InputFilePaths         []string
+		MaxRuntime             int64
+		Name                   string
+		NoCollector            bool
+		NoJSON                 bool
+		Random                 bool
+		ReportFile             string
+		Session                Session
+		newExperimentBuilderFn func(experimentName string) (model.ExperimentBuilder, error)
+		newInputLoaderFn       func(inputPolicy model.InputPolicy) inputLoader
+		newSubmitterFn         func(ctx context.Context) (engine.Submitter, error)
+		newSaverFn             func(experiment model.Experiment) (engine.Saver, error)
+		newInputProcessorFn    func(experiment model.Experiment, inputList []model.OOAPIURLInfo, saver engine.Saver, submitter engine.Submitter) inputProcessor
+	}
+	type args struct {
+		ctx context.Context
+	}
+	tests := []struct {
+		name      string
+		fields    fields
+		args      args
+		expectErr error
+	}{{
+		name: "cannot construct an experiment builder",
+		fields: fields{
+			newExperimentBuilderFn: func(experimentName string) (model.ExperimentBuilder, error) {
+				return nil, errMocked
+			},
+		},
+		args:      args{},
+		expectErr: errMocked,
+	}, {
+		name: "cannot load input",
+		fields: fields{
+			newExperimentBuilderFn: func(experimentName string) (model.ExperimentBuilder, error) {
+				eb := &mocks.ExperimentBuilder{
+					MockInputPolicy: func() model.InputPolicy {
+						return model.InputOptional
+					},
+				}
+				return eb, nil
+			},
+			newInputLoaderFn: func(inputPolicy model.InputPolicy) inputLoader {
+				return &mocks.ExperimentInputLoader{
+					MockLoad: func(ctx context.Context) ([]model.OOAPIURLInfo, error) {
+						return nil, errMocked
+					},
+				}
+			},
+		},
+		args:      args{},
+		expectErr: errMocked,
+	}, {
+		name: "cannot set options",
+		fields: fields{
+			newExperimentBuilderFn: func(experimentName string) (model.ExperimentBuilder, error) {
+				eb := &mocks.ExperimentBuilder{
+					MockInputPolicy: func() model.InputPolicy {
+						return model.InputOptional
+					},
+					MockSetOptionsAny: func(options map[string]any) error {
+						return errMocked
+					},
+				}
+				return eb, nil
+			},
+			newInputLoaderFn: func(inputPolicy model.InputPolicy) inputLoader {
+				return &mocks.ExperimentInputLoader{
+					MockLoad: func(ctx context.Context) ([]model.OOAPIURLInfo, error) {
+						return []model.OOAPIURLInfo{}, nil
+					},
+				}
+			},
+		},
+		args:      args{},
+		expectErr: errMocked,
+	}, {
+		name: "cannot create new submitter",
+		fields: fields{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+			newExperimentBuilderFn: func(experimentName string) (model.ExperimentBuilder, error) {
+				eb := &mocks.ExperimentBuilder{
+					MockInputPolicy: func() model.InputPolicy {
+						return model.InputOptional
+					},
+					MockSetOptionsAny: func(options map[string]any) error {
+						return nil
+					},
+					MockNewExperiment: func() model.Experiment {
+						exp := &mocks.Experiment{
+							MockKibiBytesReceived: func() float64 {
+								return 0
+							},
+							MockKibiBytesSent: func() float64 {
+								return 0
+							},
+						}
+						return exp
+					},
+				}
+				return eb, nil
+			},
+			newInputLoaderFn: func(inputPolicy model.InputPolicy) inputLoader {
+				return &mocks.ExperimentInputLoader{
+					MockLoad: func(ctx context.Context) ([]model.OOAPIURLInfo, error) {
+						return []model.OOAPIURLInfo{}, nil
+					},
+				}
+			},
+			newSubmitterFn: func(ctx context.Context) (engine.Submitter, error) {
+				return nil, errMocked
+			},
+		},
+		args:      args{},
+		expectErr: errMocked,
+	}, {
+		name: "cannot create new saver",
+		fields: fields{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+			newExperimentBuilderFn: func(experimentName string) (model.ExperimentBuilder, error) {
+				eb := &mocks.ExperimentBuilder{
+					MockInputPolicy: func() model.InputPolicy {
+						return model.InputOptional
+					},
+					MockSetOptionsAny: func(options map[string]any) error {
+						return nil
+					},
+					MockNewExperiment: func() model.Experiment {
+						exp := &mocks.Experiment{
+							MockKibiBytesReceived: func() float64 {
+								return 0
+							},
+							MockKibiBytesSent: func() float64 {
+								return 0
+							},
+						}
+						return exp
+					},
+				}
+				return eb, nil
+			},
+			newInputLoaderFn: func(inputPolicy model.InputPolicy) inputLoader {
+				return &mocks.ExperimentInputLoader{
+					MockLoad: func(ctx context.Context) ([]model.OOAPIURLInfo, error) {
+						return []model.OOAPIURLInfo{}, nil
+					},
+				}
+			},
+			newSubmitterFn: func(ctx context.Context) (engine.Submitter, error) {
+				return &mocks.Submitter{}, nil
+			},
+			newSaverFn: func(experiment model.Experiment) (engine.Saver, error) {
+				return nil, errMocked
+			},
+		},
+		args:      args{},
+		expectErr: errMocked,
+	}, {
+		name: "input processor fails",
+		fields: fields{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+			newExperimentBuilderFn: func(experimentName string) (model.ExperimentBuilder, error) {
+				eb := &mocks.ExperimentBuilder{
+					MockInputPolicy: func() model.InputPolicy {
+						return model.InputOptional
+					},
+					MockSetOptionsAny: func(options map[string]any) error {
+						return nil
+					},
+					MockNewExperiment: func() model.Experiment {
+						exp := &mocks.Experiment{
+							MockKibiBytesReceived: func() float64 {
+								return 0
+							},
+							MockKibiBytesSent: func() float64 {
+								return 0
+							},
+						}
+						return exp
+					},
+				}
+				return eb, nil
+			},
+			newInputLoaderFn: func(inputPolicy model.InputPolicy) inputLoader {
+				return &mocks.ExperimentInputLoader{
+					MockLoad: func(ctx context.Context) ([]model.OOAPIURLInfo, error) {
+						return []model.OOAPIURLInfo{}, nil
+					},
+				}
+			},
+			newSubmitterFn: func(ctx context.Context) (engine.Submitter, error) {
+				return &mocks.Submitter{}, nil
+			},
+			newSaverFn: func(experiment model.Experiment) (engine.Saver, error) {
+				return &mocks.Saver{}, nil
+			},
+			newInputProcessorFn: func(experiment model.Experiment, inputList []model.OOAPIURLInfo,
+				saver engine.Saver, submitter engine.Submitter) inputProcessor {
+				return &mocks.ExperimentInputProcessor{
+					MockRun: func(ctx context.Context) error {
+						return errMocked
+					},
+				}
+			},
+		},
+		args:      args{},
+		expectErr: errMocked,
+	}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ed := &Experiment{
+				Annotations:            tt.fields.Annotations,
+				ExtraOptions:           tt.fields.ExtraOptions,
+				Inputs:                 tt.fields.Inputs,
+				InputFilePaths:         tt.fields.InputFilePaths,
+				MaxRuntime:             tt.fields.MaxRuntime,
+				Name:                   tt.fields.Name,
+				NoCollector:            tt.fields.NoCollector,
+				NoJSON:                 tt.fields.NoJSON,
+				Random:                 tt.fields.Random,
+				ReportFile:             tt.fields.ReportFile,
+				Session:                tt.fields.Session,
+				newExperimentBuilderFn: tt.fields.newExperimentBuilderFn,
+				newInputLoaderFn:       tt.fields.newInputLoaderFn,
+				newSubmitterFn:         tt.fields.newSubmitterFn,
+				newSaverFn:             tt.fields.newSaverFn,
+				newInputProcessorFn:    tt.fields.newInputProcessorFn,
+			}
+			err := ed.Run(tt.args.ctx)
+			if !errors.Is(err, tt.expectErr) {
+				t.Fatalf("Experiment.Run() error = %v, expectErr %v", err, tt.expectErr)
+			}
+		})
+	}
+}

internal/oonirun/v1.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/url"
 )
 
@@ -50,7 +51,7 @@ func v1Measure(ctx context.Context, config *LinkConfig, URL string) error {
 		if pu.Host != "nettest" {
 			return ErrInvalidV1URLHost
 		}
-		if pu.Path != "" {
+		if pu.Path != "" && pu.Path != "/" {
 			return ErrInvalidV1URLPath
 		}
 	default:
@@ -58,33 +59,50 @@ func v1Measure(ctx context.Context, config *LinkConfig, URL string) error {
 	}
 	name := pu.Query().Get("tn")
 	if name == "" {
-		return ErrInvalidV1URLQueryArgument
+		return fmt.Errorf("%w: empty test name", ErrInvalidV1URLQueryArgument)
 	}
 	var inputs []string
-	if ra := pu.Query().Get("ta"); ra != "" {
-		pa, err := url.QueryUnescape(ra)
+	if ta := pu.Query().Get("ta"); ta != "" {
+		inputs, err = v1ParseArguments(ta)
 		if err != nil {
 			return err
 		}
-		var arguments v1Arguments
-		if err := json.Unmarshal([]byte(pa), &arguments); err != nil {
-			return err
-		}
-		inputs = arguments.URLs
 	}
-	// TODO(bassosimone): reject mv < 1.2.0
+	if mv := pu.Query().Get("mv"); mv != "1.2.0" {
+		return fmt.Errorf("%w: unknown minimum version", ErrInvalidV1URLQueryArgument)
+	}
 	exp := &Experiment{
-		Annotations:    config.Annotations,
-		ExtraOptions:   nil, // no way to specify with v1 URLs
-		Inputs:         inputs,
-		InputFilePaths: nil,
-		MaxRuntime:     config.MaxRuntime,
-		Name:           name,
-		NoCollector:    config.NoCollector,
-		NoJSON:         config.NoJSON,
-		Random:         config.Random,
-		ReportFile:     config.ReportFile,
-		Session:        config.Session,
+		Annotations:            config.Annotations,
+		ExtraOptions:           nil, // no way to specify with v1 URLs
+		Inputs:                 inputs,
+		InputFilePaths:         nil,
+		MaxRuntime:             config.MaxRuntime,
+		Name:                   name,
+		NoCollector:            config.NoCollector,
+		NoJSON:                 config.NoJSON,
+		Random:                 config.Random,
+		ReportFile:             config.ReportFile,
+		Session:                config.Session,
+		newExperimentBuilderFn: nil,
+		newInputLoaderFn:       nil,
+		newSubmitterFn:         nil,
+		newSaverFn:             nil,
+		newInputProcessorFn:    nil,
 	}
 	return exp.Run(ctx)
 }
+
+// v1ParseArguments parses the `ta` field of the query string.
+func v1ParseArguments(ta string) ([]string, error) {
+	var inputs []string
+	pa, err := url.QueryUnescape(ta)
+	if err != nil {
+		return nil, fmt.Errorf("%w: %s", ErrInvalidV1URLQueryArgument, err.Error())
+	}
+	var arguments v1Arguments
+	if err := json.Unmarshal([]byte(pa), &arguments); err != nil {
+		return nil, fmt.Errorf("%w: %s", ErrInvalidV1URLQueryArgument, err.Error())
+	}
+	inputs = arguments.URLs
+	return inputs, nil
+}

internal/oonirun/v1_test.go

@@ -2,13 +2,60 @@ package oonirun
 
 import (
 	"context"
+	"errors"
+	"net/http"
+	"strings"
 	"testing"
 
 	"github.com/ooni/probe-cli/v3/internal/kvstore"
+	"github.com/ooni/probe-cli/v3/internal/model"
+	"github.com/ooni/probe-cli/v3/internal/model/mocks"
+	"github.com/ooni/probe-cli/v3/internal/testingx"
 )
 
-// TODO(bassosimone): it would be cool to write unit tests. However, to do that
-// we need to ~redesign the engine package for unit-testability.
+func newMinimalFakeSession() *mocks.Session {
+	return &mocks.Session{
+		MockLogger: func() model.Logger {
+			return model.DiscardLogger
+		},
+		MockNewExperimentBuilder: func(name string) (model.ExperimentBuilder, error) {
+			eb := &mocks.ExperimentBuilder{
+				MockInputPolicy: func() model.InputPolicy {
+					return model.InputNone
+				},
+				MockSetOptionsAny: func(options map[string]any) error {
+					return nil
+				},
+				MockNewExperiment: func() model.Experiment {
+					exp := &mocks.Experiment{
+						MockMeasureAsync: func(ctx context.Context, input string) (<-chan *model.Measurement, error) {
+							out := make(chan *model.Measurement)
+							go func() {
+								defer close(out)
+								ff := &testingx.FakeFiller{}
+								var meas model.Measurement
+								ff.Fill(&meas)
+								out <- &meas
+							}()
+							return out, nil
+						},
+						MockKibiBytesReceived: func() float64 {
+							return 1.1
+						},
+						MockKibiBytesSent: func() float64 {
+							return 0.1
+						},
+					}
+					return exp
+				},
+			}
+			return eb, nil
+		},
+		MockDefaultHTTPClient: func() model.HTTPClient {
+			return http.DefaultClient
+		},
+	}
+}
 
 func TestOONIRunV1Link(t *testing.T) {
 	ctx := context.Background()
@@ -23,7 +70,7 @@ func TestOONIRunV1Link(t *testing.T) {
 		NoJSON:      true,
 		Random:      false,
 		ReportFile:  "",
-		Session:     newSession(ctx, t),
+		Session:     newMinimalFakeSession(),
 	}
 	r := NewLinkRunner(config, "https://run.ooni.io/nettest?tn=example&mv=1.2.0")
 	if err := r.Run(ctx); err != nil {
@@ -34,3 +81,188 @@ func TestOONIRunV1Link(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestV1MeasureInvalidURL(t *testing.T) {
+	t.Run("URL does not parse", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "\t"
+		err := v1Measure(ctx, config, URL)
+		if err == nil || !strings.HasSuffix(err.Error(), "invalid control character in URL") {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with https:// URL and invalid hostname", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "https://run.ooni.nu/nettest"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLHost) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with https:// URL and invalid path", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "https://run.ooni.io/antani"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLPath) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with ooni:// URL and invalid host", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "ooni://antani"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLHost) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with ooni:// URL and path", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "ooni://nettest/x"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLPath) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with invalid URL scheme", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "antani://nettest"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLScheme) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with empty test name", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "ooni://nettest/"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLQueryArgument) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with invalid JSON and explicit / as path", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "ooni://nettest/?tn=web_connectivity&ta=123x"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLQueryArgument) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with invalid JSON and empty path", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "ooni://nettest?tn=web_connectivity&ta=123x"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLQueryArgument) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+
+	t.Run("with missing minimum version", func(t *testing.T) {
+		ctx := context.Background()
+		config := &LinkConfig{
+			Session: &mocks.Session{
+				MockLogger: func() model.Logger {
+					return model.DiscardLogger
+				},
+			},
+		}
+		URL := "ooni://nettest?tn=example"
+		err := v1Measure(ctx, config, URL)
+		if !errors.Is(err, ErrInvalidV1URLQueryArgument) {
+			t.Fatal("unexpected err", err)
+		}
+	})
+}
+
+func TestV1ParseArguments(t *testing.T) {
+	t.Run("with invalid test arguments", func(t *testing.T) {
+		// "[QueryUnescape] returns an error if any % is not followed by two hexadecimal digits."
+		out, err := v1ParseArguments("%KK")
+		if !errors.Is(err, ErrInvalidV1URLQueryArgument) {
+			t.Fatal("unexpected err", err)
+		}
+		if len(out) > 0 {
+			t.Fatal("expected no output")
+		}
+	})
+
+	t.Run("with valid arguments", func(t *testing.T) {
+		out, err := v1ParseArguments("%7B%22urls%22%3A%5B%22https%3A%2F%2Fexample.com%2F%22%5D%7D")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(out) != 1 || out[0] != "https://example.com/" {
+			t.Fatal("unexpected out", out)
+		}
+	})
+}

internal/oonirun/v2.go

@@ -24,6 +24,10 @@ var (
 	// v2CountEmptyNettestNames counts the number of cases in which we have been
 	// given an empty nettest name, which is useful for testing.
 	v2CountEmptyNettestNames = &atomicx.Int64{}
+
+	// v2CountFailedExperiments countes the number of failed experiments
+	// and is useful when testing this package
+	v2CountFailedExperiments = &atomicx.Int64{}
 )
 
 // v2Descriptor describes a single nettest to run.
@@ -172,20 +176,26 @@ func v2MeasureDescriptor(ctx context.Context, config *LinkConfig, desc *v2Descri
 			continue
 		}
 		exp := &Experiment{
-			Annotations:    config.Annotations,
-			ExtraOptions:   nettest.Options,
-			Inputs:         nettest.Inputs,
-			InputFilePaths: nil,
-			MaxRuntime:     config.MaxRuntime,
-			Name:           nettest.TestName,
-			NoCollector:    config.NoCollector,
-			NoJSON:         config.NoJSON,
-			Random:         config.Random,
-			ReportFile:     config.ReportFile,
-			Session:        config.Session,
+			Annotations:            config.Annotations,
+			ExtraOptions:           nettest.Options,
+			Inputs:                 nettest.Inputs,
+			InputFilePaths:         nil,
+			MaxRuntime:             config.MaxRuntime,
+			Name:                   nettest.TestName,
+			NoCollector:            config.NoCollector,
+			NoJSON:                 config.NoJSON,
+			Random:                 config.Random,
+			ReportFile:             config.ReportFile,
+			Session:                config.Session,
+			newExperimentBuilderFn: nil,
+			newInputLoaderFn:       nil,
+			newSubmitterFn:         nil,
+			newSaverFn:             nil,
+			newInputProcessorFn:    nil,
 		}
 		if err := exp.Run(ctx); err != nil {
 			logger.Warnf("cannot run experiment: %s", err.Error())
+			v2CountFailedExperiments.Add(1)
 			continue
 		}
 	}

internal/oonirun/v2_test.go

@@ -10,13 +10,11 @@ import (
 	"time"
 
 	"github.com/ooni/probe-cli/v3/internal/kvstore"
+	"github.com/ooni/probe-cli/v3/internal/model"
 	"github.com/ooni/probe-cli/v3/internal/model/mocks"
 	"github.com/ooni/probe-cli/v3/internal/runtimex"
 )
 
-// TODO(bassosimone): it would be cool to write unit tests. However, to do that
-// we need to ~redesign the engine package for unit-testability.
-
 func TestOONIRunV2LinkCommonCase(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		descriptor := &v2Descriptor{
@@ -48,7 +46,7 @@ func TestOONIRunV2LinkCommonCase(t *testing.T) {
 		NoJSON:      true,
 		Random:      false,
 		ReportFile:  "",
-		Session:     newSession(ctx, t),
+		Session:     newMinimalFakeSession(),
 	}
 	r := NewLinkRunner(config, server.URL)
 	if err := r.Run(ctx); err != nil {
@@ -95,7 +93,7 @@ func TestOONIRunV2LinkCannotUpdateCache(t *testing.T) {
 		NoJSON:      true,
 		Random:      false,
 		ReportFile:  "",
-		Session:     newSession(ctx, t),
+		Session:     newMinimalFakeSession(),
 	}
 	r := NewLinkRunner(config, server.URL)
 	err := r.Run(ctx)
@@ -135,7 +133,7 @@ func TestOONIRunV2LinkWithoutAcceptChanges(t *testing.T) {
 		NoJSON:      true,
 		Random:      false,
 		ReportFile:  "",
-		Session:     newSession(ctx, t),
+		Session:     newMinimalFakeSession(),
 	}
 	r := NewLinkRunner(config, server.URL)
 	err := r.Run(ctx)
@@ -161,7 +159,7 @@ func TestOONIRunV2LinkNilDescriptor(t *testing.T) {
 		NoJSON:      true,
 		Random:      false,
 		ReportFile:  "",
-		Session:     newSession(ctx, t),
+		Session:     newMinimalFakeSession(),
 	}
 	r := NewLinkRunner(config, server.URL)
 	if err := r.Run(ctx); err != nil {
@@ -170,6 +168,7 @@ func TestOONIRunV2LinkNilDescriptor(t *testing.T) {
 }
 
 func TestOONIRunV2LinkEmptyTestName(t *testing.T) {
+	emptyTestNamesPrev := v2CountEmptyNettestNames.Load()
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		descriptor := &v2Descriptor{
 			Name:        "",
@@ -200,14 +199,14 @@ func TestOONIRunV2LinkEmptyTestName(t *testing.T) {
 		NoJSON:      true,
 		Random:      false,
 		ReportFile:  "",
-		Session:     newSession(ctx, t),
+		Session:     newMinimalFakeSession(),
 	}
 	r := NewLinkRunner(config, server.URL)
 	if err := r.Run(ctx); err != nil {
 		t.Fatal(err)
 	}
-	if v2CountEmptyNettestNames.Load() != 1 {
-		t.Fatal("expected to see 1 instance of empty nettest names")
+	if v2CountEmptyNettestNames.Load() != emptyTestNamesPrev+1 {
+		t.Fatal("expected to see 1 more instance of empty nettest names")
 	}
 }
 
@@ -220,6 +219,74 @@ func TestV2MeasureDescriptor(t *testing.T) {
 			t.Fatal("unexpected err", err)
 		}
 	})
+
+	t.Run("with failing experiment", func(t *testing.T) {
+		previousFailedExperiments := v2CountFailedExperiments.Load()
+		expected := errors.New("mocked error")
+		ctx := context.Background()
+		sess := newMinimalFakeSession()
+		sess.MockNewSubmitter = func(ctx context.Context) (model.Submitter, error) {
+			subm := &mocks.Submitter{
+				MockSubmit: func(ctx context.Context, m *model.Measurement) error {
+					panic("should not be called")
+				},
+			}
+			return subm, nil
+		}
+		sess.MockNewExperimentBuilder = func(name string) (model.ExperimentBuilder, error) {
+			eb := &mocks.ExperimentBuilder{
+				MockInputPolicy: func() model.InputPolicy {
+					return model.InputNone
+				},
+				MockSetOptionsAny: func(options map[string]any) error {
+					return nil
+				},
+				MockNewExperiment: func() model.Experiment {
+					exp := &mocks.Experiment{
+						MockMeasureAsync: func(ctx context.Context, input string) (<-chan *model.Measurement, error) {
+							return nil, expected
+						},
+						MockKibiBytesReceived: func() float64 {
+							return 1.1
+						},
+						MockKibiBytesSent: func() float64 {
+							return 0.1
+						},
+					}
+					return exp
+				},
+			}
+			return eb, nil
+		}
+		config := &LinkConfig{
+			AcceptChanges: false,
+			Annotations:   map[string]string{},
+			KVStore:       nil,
+			MaxRuntime:    0,
+			NoCollector:   false,
+			NoJSON:        false,
+			Random:        false,
+			ReportFile:    "",
+			Session:       sess,
+		}
+		descr := &v2Descriptor{
+			Name:        "",
+			Description: "",
+			Author:      "",
+			Nettests: []v2Nettest{{
+				Inputs:   []string{},
+				Options:  map[string]any{},
+				TestName: "example",
+			}},
+		}
+		err := v2MeasureDescriptor(ctx, config, descr)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if v2CountFailedExperiments.Load() != previousFailedExperiments+1 {
+			t.Fatal("expected to see a failed experiment")
+		}
+	})
 }
 
 func TestV2MeasureHTTPS(t *testing.T) {
@@ -239,7 +306,7 @@ func TestV2MeasureHTTPS(t *testing.T) {
 			NoJSON:      false,
 			Random:      false,
 			ReportFile:  "",
-			Session:     newSession(ctx, t),
+			Session:     newMinimalFakeSession(),
 		}
 		err := v2MeasureHTTPS(ctx, config, "")
 		if !errors.Is(err, expected) {
@@ -259,7 +326,7 @@ func TestV2MeasureHTTPS(t *testing.T) {
 			NoJSON:        false,
 			Random:        false,
 			ReportFile:    "",
-			Session:       newSession(ctx, t),
+			Session:       newMinimalFakeSession(),
 		}
 		err := v2MeasureHTTPS(ctx, config, "https://example.com") // should not use URL
 		if !errors.Is(err, context.Canceled) {

internal/runtimex/runtimex.go

@@ -11,8 +11,8 @@ func PanicOnError(err error, message string) {
 	}
 }
 
-// PanicIfFalse calls panic if assertion is false.
-func PanicIfFalse(assertion bool, message string) {
+// Assert calls panic if assertion is false.
+func Assert(assertion bool, message string) {
 	if !assertion {
 		panic(message)
 	}
@@ -20,7 +20,7 @@ func PanicIfFalse(assertion bool, message string) {
 
 // PanicIfTrue calls panic if assertion is true.
 func PanicIfTrue(assertion bool, message string) {
-	PanicIfFalse(!assertion, message)
+	Assert(!assertion, message)
 }
 
 // PanicIfNil calls panic if the given interface is nil.

internal/runtimex/runtimex_test.go

@@ -28,17 +28,17 @@ func TestPanicOnError(t *testing.T) {
 	})
 }
 
-func TestPanicIfFalse(t *testing.T) {
+func TestAssert(t *testing.T) {
 	badfunc := func(in bool, message string) (out error) {
 		defer func() {
 			out = errors.New(recover().(string))
 		}()
-		runtimex.PanicIfFalse(in, message)
+		runtimex.Assert(in, message)
 		return
 	}
 
 	t.Run("assertion is true", func(t *testing.T) {
-		runtimex.PanicIfFalse(true, "this assertion should not fail")
+		runtimex.Assert(true, "this assertion should not fail")
 	})
 
 	t.Run("assertion is false", func(t *testing.T) {

internal/tracex/event.go

@@ -33,7 +33,7 @@ func NewFailureStr(err error) FailureStr {
 	if !errors.As(err, &errWrapper) {
 		err := netxlite.NewTopLevelGenericErrWrapper(err)
 		couldConvert := errors.As(err, &errWrapper)
-		runtimex.PanicIfFalse(couldConvert, "we should have an ErrWrapper here")
+		runtimex.Assert(couldConvert, "we should have an ErrWrapper here")
 	}
 	s := errWrapper.Failure
 	if s == "" {