Close out the repository audit

cmd/weatherreporter/main.go

@@ -19,7 +19,13 @@ func main() {
 }
 
 func runCommand(args []string, stdout, stderr io.Writer, runner func(context.Context, []string, io.Writer, io.Writer) error) error {
-	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	return runCommandWithSignalContext(args, stdout, stderr, runner, signal.NotifyContext)
+}
+
+type signalContextFunc func(context.Context, ...os.Signal) (context.Context, context.CancelFunc)
+
+func runCommandWithSignalContext(args []string, stdout, stderr io.Writer, runner func(context.Context, []string, io.Writer, io.Writer) error, signalContext signalContextFunc) error {
+	ctx, stop := signalContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer stop()
 	return runner(ctx, args, stdout, stderr)
 }

cmd/weatherreporter/main_test.go

@@ -7,50 +7,30 @@ import (
 	"os"
 	"syscall"
 	"testing"
-	"time"
 )
 
-func TestRunCommandCancelsActionContextOnSignal(t *testing.T) {
-	for _, tt := range []struct {
-		name   string
-		signal os.Signal
-	}{
-		{name: "Interrupt", signal: os.Interrupt},
-		{name: "Terminate", signal: syscall.SIGTERM},
-	} {
-		t.Run(tt.name, func(t *testing.T) {
-			started := make(chan struct{})
-			done := make(chan error, 1)
-			go func() {
-				done <- runCommand(nil, io.Discard, io.Discard, func(ctx context.Context, _ []string, _, _ io.Writer) error {
-					close(started)
-					<-ctx.Done()
-					return ctx.Err()
-				})
-			}()
+func TestRunCommandBuildsCancelableSignalContext(t *testing.T) {
+	var signals []os.Signal
+	stopped := false
+	signalContext := func(parent context.Context, requested ...os.Signal) (context.Context, context.CancelFunc) {
+		signals = append([]os.Signal(nil), requested...)
+		ctx, cancel := context.WithCancel(parent)
+		cancel()
+		return ctx, func() {
+			stopped = true
+		}
+	}
 
-			select {
-			case <-started:
-			case <-time.After(time.Second):
-				t.Fatal("runner did not receive an action context")
-			}
-
-			process, err := os.FindProcess(os.Getpid())
-			if err != nil {
-				t.Fatalf("FindProcess() error = %v", err)
-			}
-			if err := process.Signal(tt.signal); err != nil {
-				t.Fatalf("Signal(%v) error = %v", tt.signal, err)
-			}
-
-			select {
-			case err := <-done:
-				if !errors.Is(err, context.Canceled) {
-					t.Fatalf("runCommand() error = %v, want context cancellation", err)
-				}
-			case <-time.After(time.Second):
-				t.Fatal("interrupt did not cancel the action context")
-			}
-		})
+	err := runCommandWithSignalContext(nil, io.Discard, io.Discard, func(ctx context.Context, _ []string, _, _ io.Writer) error {
+		return ctx.Err()
+	}, signalContext)
+	if !errors.Is(err, context.Canceled) {
+		t.Fatalf("runCommandWithSignalContext() error = %v, want context cancellation", err)
+	}
+	if len(signals) != 2 || signals[0] != os.Interrupt || signals[1] != syscall.SIGTERM {
+		t.Fatalf("requested signals = %#v, want Interrupt and SIGTERM", signals)
+	}
+	if !stopped {
+		t.Fatal("signal context stop function was not called")
 	}
 }

cmd/weatherreporter/main_unix_test.go

@@ -0,0 +1,58 @@
+//go:build unix
+
+package main
+
+import (
+	"context"
+	"errors"
+	"io"
+	"os"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestRunCommandCancelsActionContextOnSignal(t *testing.T) {
+	for _, tt := range []struct {
+		name   string
+		signal os.Signal
+	}{
+		{name: "Interrupt", signal: os.Interrupt},
+		{name: "Terminate", signal: syscall.SIGTERM},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			started := make(chan struct{})
+			done := make(chan error, 1)
+			go func() {
+				done <- runCommand(nil, io.Discard, io.Discard, func(ctx context.Context, _ []string, _, _ io.Writer) error {
+					close(started)
+					<-ctx.Done()
+					return ctx.Err()
+				})
+			}()
+
+			select {
+			case <-started:
+			case <-time.After(time.Second):
+				t.Fatal("runner did not receive an action context")
+			}
+
+			process, err := os.FindProcess(os.Getpid())
+			if err != nil {
+				t.Fatalf("FindProcess() error = %v", err)
+			}
+			if err := process.Signal(tt.signal); err != nil {
+				t.Fatalf("Signal(%v) error = %v", tt.signal, err)
+			}
+
+			select {
+			case err := <-done:
+				if !errors.Is(err, context.Canceled) {
+					t.Fatalf("runCommand() error = %v, want context cancellation", err)
+				}
+			case <-time.After(time.Second):
+				t.Fatal("interrupt did not cancel the action context")
+			}
+		})
+	}
+}