refactor: move more commands to internal/cmd (#207)

* refactor: move more commands to internal/cmd

Part of https://github.com/ooni/probe/issues/1335.

We would like all commands to be at the same level of engine
rather than inside engine (now that we can do it).

* fix: update .gitignore

* refactor: also move jafar outside engine

* We should be good now?

internal/cmd/jafar/flagx/stringarray_test.go

@@ -0,0 +1,73 @@
+package flagx_test
+
+// The code in this file is adapted from github.com/m-lab/go and more
+// specifically from <https://git.io/JJ8UA>. This file is licensed under
+// version 2.0 of the Apache License <https://git.io/JJ8Ux>.
+
+import (
+	"flag"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/ooni/probe-cli/v3/internal/cmd/jafar/flagx"
+)
+
+func TestStringArray(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []string
+		expt     flagx.StringArray
+		repr     string
+		contains string
+		wantErr  bool
+	}{
+		{
+			name:     "okay",
+			args:     []string{"a", "b"},
+			expt:     flagx.StringArray{"a", "b"},
+			repr:     `[]string{"a", "b"}`,
+			contains: "b",
+		},
+		{
+			name:     "okay-split-commas",
+			args:     []string{"a", "b", "c,d"},
+			expt:     flagx.StringArray{"a", "b", "c", "d"},
+			repr:     `[]string{"a", "b", "c", "d"}`,
+			contains: "d",
+		},
+		{
+			name:     "empty",
+			args:     []string{},
+			expt:     flagx.StringArray{},
+			repr:     `[]string{}`,
+			contains: "a",
+			wantErr:  true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			sa := &flagx.StringArray{}
+			for i := range tt.args {
+				if err := sa.Set(tt.args[i]); err != nil {
+					t.Errorf("StringArray.Set() error = %v, want nil", err)
+				}
+			}
+			v := (sa.Get().(flagx.StringArray))
+			if diff := cmp.Diff(v, tt.expt); diff != "" {
+				t.Errorf("StringArray.Get() unexpected differences %v", diff)
+			}
+			if tt.repr != sa.String() {
+				t.Errorf("StringArray.String() want = %q, got %q", tt.repr, sa.String())
+			}
+			if sa.Contains(tt.contains) == tt.wantErr {
+				t.Errorf("StringArray.Contains() want = %q, got %t", tt.repr, sa.Contains(tt.contains))
+			}
+		})
+	}
+}
+
+// Successful compilation of this function means that StringArray implements the
+// flag.Getter interface. The function need not be called.
+func assertFlagGetterStringArray(b flagx.StringArray) {
+	func(in flag.Getter) {}(&b)
+}