interp: Don't print context cancel

doc/TODO.md

@@ -13,6 +13,7 @@
 - `echo '{} {} {}' | jq` vs `echo '{} {} {}' | fq` works differently. fq currently decodes one root format and might add unknown fields etc. Maybe should work differently for `json` format?
 - `format/0` overlap with jq builtin `format/1`. What to rename it to? `decode_format`?
 - repl expression returning a value that produced lots of output can't be interrupted. This is becaus ctrl-C currently only interrupts the evaluation of the expression, outputted value is printed (`display`) by parent.
+- Rework cli/repl user interrupt (context cancel via ctrl-c), see comment in Interp.Main
 
 ### TODO and ideas
 

format/fuzz_test.go

@@ -26,11 +26,11 @@ type fuzzTestOutput struct {
 func (o fuzzTestOutput) Size() (int, int) { return 120, 25 }
 func (o fuzzTestOutput) IsTerminal() bool { return false }
 
-func (ft *fuzzTest) Stdin() io.Reader         { return bytes.NewBuffer(ft.b) } // TODO: special file?
-func (ft *fuzzTest) Stdout() interp.Output    { return fuzzTestOutput{os.Stdout} }
-func (ft *fuzzTest) Stderr() io.Writer        { return os.Stderr }
-func (ft *fuzzTest) Interrupt() chan struct{} { return nil }
-func (ft *fuzzTest) Environ() []string        { return nil }
+func (ft *fuzzTest) Stdin() io.Reader             { return bytes.NewBuffer(ft.b) } // TODO: special file?
+func (ft *fuzzTest) Stdout() interp.Output        { return fuzzTestOutput{os.Stdout} }
+func (ft *fuzzTest) Stderr() io.Writer            { return os.Stderr }
+func (ft *fuzzTest) InterruptChan() chan struct{} { return nil }
+func (ft *fuzzTest) Environ() []string            { return nil }
 func (ft *fuzzTest) Args() []string {
 	return []string{}
 }

internal/script/script.go

@@ -105,7 +105,7 @@ func (cr *CaseRun) Stderr() interp.Output {
 	return CaseRunOutput{Writer: cr.ActualStderrBuf}
 }
 
-func (cr *CaseRun) Interrupt() chan struct{} { return nil }
+func (cr *CaseRun) InterruptChan() chan struct{} { return nil }
 
 func (cr *CaseRun) Environ() []string {
 	env := []string{

pkg/cli/cli.go

@@ -34,9 +34,8 @@ func (a autoCompleterFn) Do(line []rune, pos int) (newLine [][]rune, length int)
 }
 
 type stdOS struct {
-	rl                  *readline.Instance
-	interruptSignalChan chan os.Signal
-	interruptChan       chan struct{}
+	rl            *readline.Instance
+	interruptChan chan struct{}
 }
 
 func newStandardOS() *stdOS {
@@ -44,7 +43,10 @@ func newStandardOS() *stdOS {
 	interruptSignalChan := make(chan os.Signal, 1)
 	signal.Notify(interruptSignalChan, os.Interrupt)
 	go func() {
-		defer signal.Stop(interruptSignalChan)
+		defer func() {
+			signal.Stop(interruptSignalChan)
+			close(interruptSignalChan)
+		}()
 		for range interruptSignalChan {
 			select {
 			case interruptChan <- struct{}{}:
@@ -54,8 +56,7 @@ func newStandardOS() *stdOS {
 	}()
 
 	return &stdOS{
-		interruptSignalChan: interruptSignalChan,
-		interruptChan:       interruptChan,
+		interruptChan: interruptChan,
 	}
 }
 
@@ -114,7 +115,7 @@ func (o stderrOutput) Write(p []byte) (n int, err error) { return os.Stderr.Writ
 
 func (o *stdOS) Stderr() interp.Output { return stderrOutput{fdTerminal: fdTerminal(os.Stderr.Fd())} }
 
-func (o *stdOS) Interrupt() chan struct{} { return o.interruptChan }
+func (o *stdOS) InterruptChan() chan struct{} { return o.interruptChan }
 
 func (*stdOS) Args() []string { return os.Args }
 
@@ -204,7 +205,7 @@ func (o *stdOS) Close() error {
 	if o.rl != nil {
 		o.rl.Close()
 	}
-	close(o.interruptSignalChan)
+	close(o.interruptChan)
 	return nil
 }
 

pkg/interp/internal.jq

@@ -121,5 +121,7 @@ def _decode_value(f):
   else _expected_decode_value
   end;
 
+def _is_context_canceled_error: . == "context canceled";
+
 def _error_str: "error: \(.)";
 def _errorln: ., "\n" | stderr;

pkg/interp/interp.go

@@ -106,7 +106,7 @@ type OS interface {
 	Stdin() Input
 	Stdout() Output
 	Stderr() Output
-	Interrupt() chan struct{}
+	InterruptChan() chan struct{}
 	Args() []string
 	Environ() []string
 	ConfigDir() (string, error)
@@ -446,7 +446,7 @@ func New(os OS, registry *registry.Registry) (*Interp, error) {
 		select {
 		case <-stopCh:
 			return
-		case <-os.Interrupt():
+		case <-os.InterruptChan():
 			return
 		}
 	})
@@ -486,6 +486,10 @@ func (i *Interp) Main(ctx context.Context, output Output, version string) error
 		case error:
 			if emptyErr, ok := v.(IsEmptyErrorer); ok && emptyErr.IsEmptyError() { //nolint:errorlint
 				// no output
+			} else if errors.Is(v, context.Canceled) {
+				// ignore context cancel here for now, which means user somehow interrupted the interpreter
+				// TODO: handle this inside interp.jq instead but then we probably have to do nested
+				// eval and or also use different contexts for the interpreter and reading/decoding
 			} else {
 				fmt.Fprintln(i.os.Stderr(), v)
 			}

pkg/interp/repl.jq

@@ -155,7 +155,10 @@ def _prompt:
 
 def _repl_display: _display({depth: 1});
 def _repl_on_error:
-  ( if _eval_is_compile_error then _eval_compile_error_tostring end
+  ( if _eval_is_compile_error then _eval_compile_error_tostring
+    # was interrupte by user, just ignore
+    elif _is_context_canceled_error then empty
+    end
   | (_error_str | println)
   );
 def _repl_on_compile_error: _repl_on_error;