responds to comments

cmd/exec.go

@@ -79,7 +79,7 @@ e.g., opa exec --decision /foo/bar/baz ...`,
 	cmd.Flags().VarP(params.LogLevel, "log-level", "l", "set log level")
 	cmd.Flags().Var(params.LogFormat, "log-format", "set log format")
 	cmd.Flags().StringVar(&params.LogTimestampFormat, "log-timestamp-format", "", "set log timestamp format (OPA_LOG_TIMESTAMP_FORMAT environment variable)")
-	cmd.Flags().BoolVarP(&params.StdIn, "std-in", "", false, "read input from os.Stdin rather than a static file; read timeout is 30 seconds")
+	cmd.Flags().BoolVarP(&params.StdIn, "stdin-input", "I", false, "read input document from stdin; read timeout is 30 seconds")
 	cmd.Flags().DurationVar(&params.Timeout, "timeout", 0, "set exec timeout with a Go-style duration, such as '5m 30s'. (default unlimited)")
 	addV1CompatibleFlag(cmd.Flags(), &params.V1Compatible, false)
 
@@ -267,7 +267,7 @@ func injectExplicitBundles(root map[string]interface{}, paths []string) error {
 
 func validateMinimumInput(params *exec.Params) error {
 	if !params.StdIn && len(params.Paths) == 0 {
-		return errors.New("requires at least 1 path arg, or the --std-in flag")
+		return errors.New("requires at least 1 path arg, or the --stdin-input flag")
 	}
 	return nil
 }

cmd/exec_test.go

@@ -1073,7 +1073,7 @@ func TestExecWithInvalidInputOptions(t *testing.T) {
 			expected:    "",
 		},
 		{
-			description: "no paths passed in as args should raise error if --std-in flag not set",
+			description: "no paths passed in as args should raise error if --stdin-input flag not set",
 			files: map[string]string{
 				"bundle/x.rego": `package system
 
@@ -1087,10 +1087,10 @@ func TestExecWithInvalidInputOptions(t *testing.T) {
 		}`,
 			},
 			expectError: true,
-			expected:    "requires at least 1 path arg, or the --std-in flag",
+			expected:    "requires at least 1 path arg, or the --stdin-input flag",
 		},
 		{
-			description: "should not raise error if --std-in flag is set when no paths passed in as args",
+			description: "should not raise error if --stdin-input flag is set when no paths passed in as args",
 			files: map[string]string{
 				"bundle/x.rego": `package system
 
@@ -1109,7 +1109,7 @@ func TestExecWithInvalidInputOptions(t *testing.T) {
 			expected:    "",
 		},
 		{
-			description: "should raise error if --std-in flag is set and no input is given",
+			description: "should raise error if --stdin-input flag is set and no input is given",
 			files: map[string]string{
 				"bundle/x.rego": `package system
 
@@ -1125,7 +1125,7 @@ func TestExecWithInvalidInputOptions(t *testing.T) {
 			stdIn:       true,
 			input:       "",
 			expectError: true,
-			expected:    "exec error: cannot execute on empty input; please enter valid json or yaml when using the --std-in flag",
+			expected:    "exec error: cannot execute on empty input; please enter valid json or yaml when using the --stdin-input flag",
 		},
 	}
 	for _, tt := range tests {

cmd/internal/exec/exec.go

@@ -21,7 +21,7 @@ var (
 	}
 )
 
-const stdInPath = "--std-in"
+const stdInPath = "--stdin-input"
 const defaultTimeout = 30 * time.Second
 
 // Exec executes OPA against the supplied files and outputs each result.
@@ -31,7 +31,7 @@ const defaultTimeout = 30 * time.Second
 //   - specialized output formats (e.g., pretty/non-JSON outputs)
 //   - exit codes set by convention or policy (e.g,. non-empty set => error)
 //   - support for new input file formats beyond JSON and YAML
-//   - flag for setting timeout on --std-in
+//   - flag for setting timeout on --stdin-input
 func Exec(ctx context.Context, opa *sdk.OPA, params *Params) error {
 	if err := params.validateParams(); err != nil {
 		return err
@@ -62,7 +62,7 @@ func execOnStdIn() error {
 	if err != nil {
 		return err
 	} else if input == nil {
-		return errors.New("cannot execute on empty input; please enter valid json or yaml when using the --std-in flag")
+		return errors.New("cannot execute on empty input; please enter valid json or yaml when using the --stdin-input flag")
 	}
 	r.StoreDecision(&input, stdInPath)
 	return r.Close()

cmd/internal/exec/exec_test.go

@@ -127,7 +127,7 @@ func TestExec(t *testing.T) {
 			},
 		},
 		{
-			description: "should read from std-in if flag is set",
+			description: "should read from stdin-input if flag is set",
 			files: map[string]string{
 				"bundle/x.rego": `package system
 
@@ -149,7 +149,7 @@ func TestExec(t *testing.T) {
 			},
 		},
 		{
-			description: "should raise error if --std-in flag is set and no input is given",
+			description: "should raise error if --stdin-input flag is set and no input is given",
 			files: map[string]string{
 				"bundle/x.rego": `package system
 
@@ -165,8 +165,10 @@ func TestExec(t *testing.T) {
 			stdIn: true,
 			input: "",
 			assertion: func(err error) {
-				expected := "cannot execute on empty input; please enter valid json or yaml when using the --std-in flag"
-				if err == nil || err.Error() != expected {
+				expected := "cannot execute on empty input; please enter valid json or yaml when using the --stdin-input flag"
+				if err == nil {
+					t.Fatalf("expected error %q, but no error was raised", expected)
+				} else if err.Error() != expected {
 					t.Fatalf("expected error %q, got %q", expected, err.Error())
 				}
 			},

cmd/internal/exec/std_in_reader.go

@@ -15,24 +15,32 @@ type stdInReader struct {
 
 func (sr *stdInReader) ReadInput() (string, error) {
 	input := make(chan string, 1)
+	done := make(chan bool, 1)
 	var lines []string
 	in := bufio.NewScanner(sr.Reader)
-	go func() {
+	go func(isDone <-chan bool) {
 		for {
-			in.Scan()
-			line := in.Text()
-			if len(line) == 0 {
-				input <- strings.Join(lines, "\n")
+			select {
+			case <-isDone:
+				return
+			default:
+				in.Scan()
+				line := in.Text()
+				if len(line) == 0 {
+					input <- strings.Join(lines, "\n")
+					return
+				}
+				lines = append(lines, line)
 			}
-			lines = append(lines, line)
 		}
-	}()
+	}(done)
 
 	for {
 		select {
 		case i := <-input:
 			return i, nil
 		case <-time.After(sr.Timeout):
+			done <- true
 			return "", fmt.Errorf("input timed out")
 		}
 	}