feat(cli): --allow-no-properties opts a run out of the refusal

cmd/sanderling/main.go

@@ -20,23 +20,24 @@ import (
 var Version = "dev"
 
 type testOptions struct {
-	spec            string
+	spec              string
-	bundleID        string
+	bundleID          string
-	platform        string
+	platform          string
-	avd             string
+	avd               string
-	device          string
+	device            string
-	iosDevice       string
+	iosDevice         string
-	iosAppPath      string
+	iosAppPath        string
-	androidAppPath  string
+	androidAppPath    string
-	duration        time.Duration
+	duration          time.Duration
-	maxSteps        int
+	maxSteps          int
-	arm             string
+	arm               string
-	seed            int64
+	seed              int64
-	output          string
+	output            string
-	clearData       bool
+	clearData         bool
-	generator       string
+	generator         string
-	labelSource     string
+	labelSource       string
-	exitOnViolation bool
+	exitOnViolation   bool
+	allowNoProperties bool
 }
 
 const topUsage = `sanderling is a property-based UI fuzzer for mobile apps.
@@ -74,6 +75,7 @@ func parseTestArgs(args []string, stderr io.Writer) (testOptions, error) {
 	flagSet.StringVar(&options.generator, "generator", "seeded", "action generator: seeded (weighted random) or llm (model picks from the same candidate set; requires generator = llm() in the spec)")
 	flagSet.StringVar(&options.labelSource, "label-source", "visible-text", "how candidates are named to the llm generator: visible-text (what a user reads) or resource-id (the identifier the app assigned). The seeded generator picks by index and ignores this")
 	flagSet.BoolVar(&options.exitOnViolation, "exit-on-violation", false, "stop the run at the first property violation and exit 2, so CI can tell a found bug (2) from a broken harness (1)")
+	flagSet.BoolVar(&options.allowNoProperties, "allow-no-properties", false, "run a spec that registers no properties. Such a run judges nothing and can only report no violations, so it is refused by default; pass this when the run measures what the spec extracts or where the generator reaches")
 	if err := flagSet.Parse(args); err != nil {
 		return testOptions{}, err
 	}

cmd/sanderling/main_test.go

@@ -401,6 +401,30 @@ func TestParseTestArgs_ExitOnViolation(t *testing.T) {
 	}
 }
 
+// TestParseTestArgs_AllowNoPropertiesReachesThePipeline pins the opt-out the
+// extraction and portability sweeps pass. Dropped here, the guard is either
+// unreachable or permanent: a sweep that deliberately judges nothing cannot ask
+// for it, and every other run keeps the false green the guard exists to stop.
+func TestParseTestArgs_AllowNoPropertiesReachesThePipeline(t *testing.T) {
+	base := []string{"--spec", "s.ts", "--bundle-id", "com.example"}
+
+	options, err := parseTestArgs(base, io.Discard)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if pipelineOptions(options).AllowNoProperties {
+		t.Error("allowNoProperties default: got true, want false")
+	}
+
+	options, err = parseTestArgs(append(base, "--allow-no-properties"), io.Discard)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !pipelineOptions(options).AllowNoProperties {
+		t.Error("--allow-no-properties never reached the pipeline options")
+	}
+}
+
 // TestExitCode_SeparatesFoundBugsFromBrokenHarnesses pins the three statuses CI
 // reads: 0 clean, 2 the run found violations, 1 everything else. A workflow
 // that asserts "the known bug is still found" is only meaningful while 2 and 1
@@ -416,6 +440,7 @@ func TestExitCode_SeparatesFoundBugsFromBrokenHarnesses(t *testing.T) {
 		{"help", flag.ErrHelp, 0, ""},
 		{"violations found", testrun.ViolationsError{Count: 2}, 2, "violations: 2"},
 		{"broken harness", errors.New("launch app: no device"), 1, "error: launch app"},
+		{"spec judges nothing", testrun.NoPropertiesError{Spec: "s.ts"}, 1, "registers no properties"},
 	} {
 		t.Run(testCase.name, func(t *testing.T) {
 			var stderr bytes.Buffer

cmd/sanderling/test_run.go

@@ -16,22 +16,23 @@ func runTestPipeline(ctx context.Context, options testOptions, stdout io.Writer)
 // and records another, which is worth being able to test on its own.
 func pipelineOptions(options testOptions) testrun.Options {
 	return testrun.Options{
-		Spec:            options.spec,
+		Spec:              options.spec,
-		BundleID:        options.bundleID,
+		AllowNoProperties: options.allowNoProperties,
-		Platform:        options.platform,
+		BundleID:          options.bundleID,
-		AVD:             options.avd,
+		Platform:          options.platform,
-		Device:          options.device,
+		AVD:               options.avd,
-		IosDevice:       options.iosDevice,
+		Device:            options.device,
-		IosAppPath:      options.iosAppPath,
+		IosDevice:         options.iosDevice,
-		AndroidAppPath:  options.androidAppPath,
+		IosAppPath:        options.iosAppPath,
-		Duration:        options.duration,
+		AndroidAppPath:    options.androidAppPath,
-		MaxSteps:        options.maxSteps,
+		Duration:          options.duration,
-		Seed:            options.seed,
+		MaxSteps:          options.maxSteps,
-		Output:          options.output,
+		Seed:              options.seed,
-		ClearData:       options.clearData,
+		Output:            options.output,
-		Generator:       options.generator,
+		ClearData:         options.clearData,
-		LabelSource:     options.labelSource,
+		Generator:         options.generator,
-		Arm:             options.arm,
+		LabelSource:       options.labelSource,
-		ExitOnViolation: options.exitOnViolation,
+		Arm:               options.arm,
+		ExitOnViolation:   options.exitOnViolation,
 	}
 }