convert missing context key refactoring

filter/external.go

@@ -66,7 +66,7 @@ func (ecf *ExternalCmd) Apply(ctx context.Context, buf []line.Line, out pipeline
 		defer g.End()
 	}
 
-	query := ctx.Value(queryKey{}).(string)
+	query := pipeline.QueryFromContext(ctx)
 	args := append([]string(nil), ecf.args...)
 	for i, v := range args {
 		if v == "$QUERY" {

filter/external_test.go

@@ -91,7 +91,7 @@ func TestExternalCmd_CancelCleansUpGoroutine(t *testing.T) {
 	t.Errorf("goroutine leak: before=%d, after=%d", before, runtime.NumGoroutine())
 }
 
-func TestExternalCmd_ApplyPanicReturnsError(t *testing.T) {
+func TestExternalCmd_ApplyWithoutQueryContext(t *testing.T) {
 	idgen := &testIDGen{}
 
 	lines := []line.Line{
@@ -102,12 +102,9 @@ func TestExternalCmd_ApplyPanicReturnsError(t *testing.T) {
 	out := pipeline.ChanOutput(make(chan line.Line, 256))
 
 	// Call Apply with a context that does NOT have the query key set.
-	// This triggers a nil interface type assertion panic at the line:
-	//   query := ctx.Value(queryKey).(string)
-	// The bug: this panic was silently swallowed, returning nil error.
+	// QueryFromContext returns "" safely (no panic).
 	err := ecf.Apply(context.Background(), lines, out)
-	require.Error(t, err, "Apply should return an error when an internal panic occurs, not swallow it silently")
-	require.Contains(t, err.Error(), "panic")
+	require.NoError(t, err, "Apply with missing query context should not panic or error")
 }
 
 func TestExternalCmdFilter_NullSep(t *testing.T) {

filter/filter.go

@@ -1,11 +1,15 @@
 package filter
 
-import "context"
+import (
+	"context"
+
+	"github.com/peco/peco/pipeline"
+)
 
 // newContext initializes the context so that it is suitable
 // to be passed to `Run()`
 func newContext(ctx context.Context, query string) context.Context {
-	return context.WithValue(ctx, queryKey{}, query)
+	return pipeline.NewQueryContext(ctx, query)
 }
 
 // sort related stuff

filter/fuzzy.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/peco/peco/internal/util"
 	"github.com/peco/peco/line"
+	"github.com/peco/peco/pipeline"
 )
 
 // NewFuzzy builds a fuzzy-finder type of filter.
@@ -40,7 +41,7 @@ func (ff Fuzzy) String() string {
 }
 
 func (ff *Fuzzy) applyInternal(ctx context.Context, lines []line.Line, emit func(line.Line)) error {
-	originalQuery := ctx.Value(queryKey{}).(string)
+	originalQuery := pipeline.QueryFromContext(ctx)
 
 	// Parse negative terms and compile them as case-insensitive regexps
 	posTerms, negTerms := SplitQueryTerms(originalQuery)

filter/interface.go

@@ -15,7 +15,6 @@ var ErrFilterNotFound = errors.New("specified filter was not found")
 
 var ignoreCaseFlags = regexpFlagList([]string{"i"})
 var defaultFlags = regexpFlagList{}
-type queryKey struct{}
 
 // DefaultCustomFilterBufferThreshold is the default value
 // for BufferThreshold setting on CustomFilters.

filter/regexp.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/peco/peco/internal/util"
 	"github.com/peco/peco/line"
+	"github.com/peco/peco/pipeline"
 )
 
 func (r regexpFlagList) flags(_ string) []string {
@@ -153,7 +154,7 @@ func (f *regexpQueryFactory) Compile(s string, flags regexpFlags, quotemeta bool
 }
 
 func (rf *Regexp) applyInternal(ctx context.Context, lines []line.Line, emit func(line.Line)) error {
-	query := ctx.Value(queryKey{}).(string)
+	query := pipeline.QueryFromContext(ctx)
 	posRegexps, negRegexps, err := rf.factory.Compile(query, rf.flags, rf.quotemeta)
 	if err != nil {
 		return fmt.Errorf("failed to compile queries as regular expression: %w", err)

pipeline/pipeline.go

@@ -9,6 +9,19 @@ import (
 	"github.com/peco/peco/line"
 )
 
+type queryContextKey struct{}
+
+// NewQueryContext returns a context with the query string stored under a typed key.
+func NewQueryContext(ctx context.Context, query string) context.Context {
+	return context.WithValue(ctx, queryContextKey{}, query)
+}
+
+// QueryFromContext retrieves the query string from the context.
+func QueryFromContext(ctx context.Context) string {
+	v, _ := ctx.Value(queryContextKey{}).(string)
+	return v
+}
+
 func NilOutput(ctx context.Context) ChanOutput {
 	ch := make(chan line.Line)
 	go func() {
@@ -86,7 +99,7 @@ func (p *Pipeline) SetDestination(d Destination) {
 // called while `Run` is running.
 func (p *Pipeline) Run(ctx context.Context) (err error) {
 	if pdebug.Enabled {
-		g := pdebug.Marker("Pipeline.Run (%s)", ctx.Value("query")).BindError(&err)
+		g := pdebug.Marker("Pipeline.Run (%s)", QueryFromContext(ctx)).BindError(&err)
 		defer g.End()
 	}
 	p.mutex.Lock()

pipeline/pipeline_test.go

@@ -108,6 +108,23 @@ func (r *Receiver) Accept(ctx context.Context, in <-chan line.Line, out ChanOutp
 	}
 }
 
+func TestQueryContext(t *testing.T) {
+	t.Run("round-trip", func(t *testing.T) {
+		ctx := NewQueryContext(context.Background(), "hello")
+		got := QueryFromContext(ctx)
+		if got != "hello" {
+			t.Fatalf("expected %q, got %q", "hello", got)
+		}
+	})
+
+	t.Run("missing key returns empty", func(t *testing.T) {
+		got := QueryFromContext(context.Background())
+		if got != "" {
+			t.Fatalf("expected empty string, got %q", got)
+		}
+	})
+}
+
 func TestPipeline(t *testing.T) {
 	src := NewLineFeeder(strings.NewReader(`foo
 bar