feat: add dry-run pipeline and automated tests

cmd/fmrtx/main.go

@@ -5,14 +5,18 @@ import (
     "fmt"
     "log"
     "net/http"
+    "os"
 
     cfgpkg "github.com/jan/fm-rds-tx/internal/config"
     ctrlpkg "github.com/jan/fm-rds-tx/internal/control"
+    drypkg "github.com/jan/fm-rds-tx/internal/dryrun"
 )
 
 func main() {
     configPath := flag.String("config", "", "path to JSON config")
     printConfig := flag.Bool("print-config", false, "print effective config and exit")
+    dryRun := flag.Bool("dry-run", false, "run no-hardware dry-run output")
+    dryOutput := flag.String("dry-output", "-", "dry-run output path or - for stdout")
     flag.Parse()
 
     cfg, err := cfgpkg.Load(*configPath)
@@ -25,6 +29,17 @@ func main() {
         return
     }
 
+    if *dryRun {
+        frame := drypkg.Generate(cfg)
+        if err := drypkg.WriteJSON(*dryOutput, frame); err != nil {
+            log.Fatalf("dry-run failed: %v", err)
+        }
+        if *dryOutput != "" && *dryOutput != "-" {
+            fmt.Fprintf(os.Stderr, "dry run frame written to %s\n", *dryOutput)
+        }
+        return
+    }
+
     srv := ctrlpkg.NewServer(cfg)
     log.Printf("fm-rds-tx listening on %s", cfg.Control.ListenAddress)
     log.Fatal(http.ListenAndServe(cfg.Control.ListenAddress, srv.Handler()))

docs/README.md

@@ -6,6 +6,7 @@
 - `go test ./...`
 - `go run ./cmd/fmrtx -print-config`
 - `go run ./cmd/fmrtx -config docs/config.sample.json`
+- `go run ./cmd/fmrtx --dry-run --dry-output build/dryrun/frame.json`
 
 ### Internal DSP module
 - `cd internal`
@@ -15,3 +16,8 @@
 - `cd examples`
 - `go test ./...`
 - `go run ./soapy_simulated`
+
+## Dry run
+
+The dry-run mode generates a synthetic, hardware-free frame summary based on the current config.
+It is intended as a no-hardware smoke path for the CLI and config/control-adjacent logic.

internal/config/config_test.go

@@ -0,0 +1,37 @@
+package config
+
+import (
+    "os"
+    "path/filepath"
+    "testing"
+)
+
+func TestDefaultValidate(t *testing.T) {
+    cfg := Default()
+    if err := cfg.Validate(); err != nil {
+        t.Fatalf("default config invalid: %v", err)
+    }
+}
+
+func TestLoadAndValidate(t *testing.T) {
+    dir := t.TempDir()
+    path := filepath.Join(dir, "config.json")
+    if err := os.WriteFile(path, []byte(`{"fm":{"frequencyMHz":99.9},"backend":{"kind":"file","outputPath":"out.f32"},"control":{"listenAddress":"127.0.0.1:8088"}}`), 0o644); err != nil {
+        t.Fatalf("write config: %v", err)
+    }
+    cfg, err := Load(path)
+    if err != nil {
+        t.Fatalf("load config: %v", err)
+    }
+    if cfg.FM.FrequencyMHz != 99.9 {
+        t.Fatalf("unexpected frequency: %v", cfg.FM.FrequencyMHz)
+    }
+}
+
+func TestValidateRejectsBadFrequency(t *testing.T) {
+    cfg := Default()
+    cfg.FM.FrequencyMHz = 200
+    if err := cfg.Validate(); err == nil {
+        t.Fatal("expected validation error")
+    }
+}

internal/control/control_test.go

@@ -0,0 +1,37 @@
+package control
+
+import (
+    "encoding/json"
+    "net/http"
+    "net/http/httptest"
+    "testing"
+
+    cfgpkg "github.com/jan/fm-rds-tx/internal/config"
+)
+
+func TestHealthz(t *testing.T) {
+    srv := NewServer(cfgpkg.Default())
+    req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
+    rec := httptest.NewRecorder()
+    srv.Handler().ServeHTTP(rec, req)
+    if rec.Code != http.StatusOK {
+        t.Fatalf("unexpected status: %d", rec.Code)
+    }
+}
+
+func TestStatus(t *testing.T) {
+    srv := NewServer(cfgpkg.Default())
+    req := httptest.NewRequest(http.MethodGet, "/status", nil)
+    rec := httptest.NewRecorder()
+    srv.Handler().ServeHTTP(rec, req)
+    if rec.Code != http.StatusOK {
+        t.Fatalf("unexpected status: %d", rec.Code)
+    }
+    var body map[string]any
+    if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+        t.Fatalf("decode body: %v", err)
+    }
+    if body["service"] != "fm-rds-tx" {
+        t.Fatalf("unexpected service: %v", body["service"])
+    }
+}

internal/dryrun/dryrun.go

@@ -0,0 +1,65 @@
+package dryrun
+
+import (
+    "encoding/json"
+    "fmt"
+    "os"
+    "path/filepath"
+
+    cfgpkg "github.com/jan/fm-rds-tx/internal/config"
+)
+
+type FrameSummary struct {
+    Mode           string    `json:"mode"`
+    FrequencyMHz   float64   `json:"frequencyMHz"`
+    StereoEnabled  bool      `json:"stereoEnabled"`
+    RDSEnabled     bool      `json:"rdsEnabled"`
+    SampleRateHz   int       `json:"sampleRateHz"`
+    CompositeRate  int       `json:"compositeRateHz"`
+    PilotLevel     float64   `json:"pilotLevel"`
+    RDSInjection   float64   `json:"rdsInjection"`
+    OutputDrive    float64   `json:"outputDrive"`
+    PreviewSamples []float64 `json:"previewSamples"`
+}
+
+func Generate(cfg cfgpkg.Config) FrameSummary {
+    preview := make([]float64, 16)
+    base := cfg.Audio.Gain * cfg.FM.OutputDrive
+    for i := range preview {
+        sign := 1.0
+        if i%2 == 1 {
+            sign = -1.0
+        }
+        preview[i] = sign * base * float64(i+1) / 16.0
+    }
+    return FrameSummary{
+        Mode:           "dry-run",
+        FrequencyMHz:   cfg.FM.FrequencyMHz,
+        StereoEnabled:  cfg.FM.StereoEnabled,
+        RDSEnabled:     cfg.RDS.Enabled,
+        SampleRateHz:   cfg.Audio.SampleRate,
+        CompositeRate:  cfg.FM.CompositeRateHz,
+        PilotLevel:     cfg.FM.PilotLevel,
+        RDSInjection:   cfg.FM.RDSInjection,
+        OutputDrive:    cfg.FM.OutputDrive,
+        PreviewSamples: preview,
+    }
+}
+
+func WriteJSON(path string, frame FrameSummary) error {
+    data, err := json.MarshalIndent(frame, "", "  ")
+    if err != nil {
+        return fmt.Errorf("marshal dry-run frame: %w", err)
+    }
+    if path == "" || path == "-" {
+        _, err = os.Stdout.Write(append(data, '\n'))
+        return err
+    }
+    if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+        return fmt.Errorf("create output dir: %w", err)
+    }
+    if err := os.WriteFile(path, append(data, '\n'), 0o644); err != nil {
+        return fmt.Errorf("write dry-run frame: %w", err)
+    }
+    return nil
+}

internal/dryrun/dryrun_test.go

@@ -0,0 +1,31 @@
+package dryrun
+
+import (
+    "os"
+    "path/filepath"
+    "testing"
+
+    cfgpkg "github.com/jan/fm-rds-tx/internal/config"
+)
+
+func TestGenerate(t *testing.T) {
+    cfg := cfgpkg.Default()
+    frame := Generate(cfg)
+    if frame.Mode != "dry-run" {
+        t.Fatalf("unexpected mode: %s", frame.Mode)
+    }
+    if len(frame.PreviewSamples) != 16 {
+        t.Fatalf("unexpected preview length: %d", len(frame.PreviewSamples))
+    }
+}
+
+func TestWriteJSONFile(t *testing.T) {
+    dir := t.TempDir()
+    out := filepath.Join(dir, "frame.json")
+    if err := WriteJSON(out, Generate(cfgpkg.Default())); err != nil {
+        t.Fatalf("WriteJSON failed: %v", err)
+    }
+    if _, err := os.Stat(out); err != nil {
+        t.Fatalf("expected output file: %v", err)
+    }
+}

scripts/check.ps1

@@ -1,5 +1,6 @@
 $ErrorActionPreference = "Stop"
 go test ./...
+go run ./cmd/fmrtx --dry-run --dry-output build/dryrun/frame.json
 Push-Location internal
 go test ./...
 Pop-Location

scripts/run.ps1

@@ -1,2 +1,2 @@
 $ErrorActionPreference = "Stop"
-go run ./cmd/fmrtx -config docs/config.sample.json
+go run ./cmd/fmrtx --dry-run --dry-output build/dryrun/frame.json