refactor(jsoncommentstrip): replace go-jsoncommentstrip with custom JSON comment stripping

2026-03-14 09:59:52 -04:00
parent d79b812467
commit 8939f31d55
3 changed files with 293 additions and 1 deletions
@@ -9,10 +9,10 @@ import (
 	"os"
 	"path/filepath"

-	"github.com/RaveNoX/go-jsoncommentstrip"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/criteria"
+	"github.com/navidrome/navidrome/utils/jsoncommentstrip"
 )

 func (s *playlists) newSyncedPlaylist(baseDir string, playlistFile string) (*model.Playlist, error) {
@@ -0,0 +1,128 @@
+// Package jsoncommentstrip provides an io.Reader that strips JavaScript-style
+// comments (// line and /* block */) from JSON input while preserving
+// comment-like sequences inside JSON string values.
+package jsoncommentstrip
+
+import (
+	"bufio"
+	"io"
+)
+
+type state int
+
+const (
+	stateNormal state = iota
+	stateInString
+	stateInStringEscape
+	stateMaybeComment  // saw '/'
+	stateLineComment   // inside // ...
+	stateBlockComment  // inside /* ... */
+	stateMaybeBlockEnd // saw '*' inside block comment
+)
+
+type reader struct {
+	r     *bufio.Reader
+	state state
+}
+
+// NewReader returns an io.Reader that strips JSON comments from the
+// underlying reader. It removes single-line comments (// to end of line)
+// and block comments (/* ... */), while preserving comment-like sequences
+// that appear inside JSON string values.
+func NewReader(r io.Reader) io.Reader {
+	return &reader{
+		r:     bufio.NewReader(r),
+		state: stateNormal,
+	}
+}
+
+func (cr *reader) Read(p []byte) (int, error) {
+	n := 0
+	for n < len(p) {
+		b, err := cr.r.ReadByte()
+		if err != nil {
+			if cr.state == stateMaybeComment {
+				// Emit the pending '/' before returning EOF
+				p[n] = '/'
+				n++
+				cr.state = stateNormal
+			}
+			return n, err
+		}
+
+		switch cr.state {
+		case stateNormal:
+			switch b {
+			case '"':
+				p[n] = b
+				n++
+				cr.state = stateInString
+			case '/':
+				cr.state = stateMaybeComment
+			default:
+				p[n] = b
+				n++
+			}
+
+		case stateInString:
+			p[n] = b
+			n++
+			switch b {
+			case '\\':
+				cr.state = stateInStringEscape
+			case '"':
+				cr.state = stateNormal
+			}
+
+		case stateInStringEscape:
+			p[n] = b
+			n++
+			cr.state = stateInString
+
+		case stateMaybeComment:
+			switch b {
+			case '/':
+				cr.state = stateLineComment
+			case '*':
+				cr.state = stateBlockComment
+			default:
+				// The '/' was not a comment start; emit it and the current byte
+				p[n] = '/'
+				n++
+				if n < len(p) {
+					p[n] = b
+					n++
+				} else {
+					// We need to "unread" the current byte since buffer is full
+					_ = cr.r.UnreadByte()
+				}
+				cr.state = stateNormal
+			}
+
+		case stateLineComment:
+			if b == '\n' || b == '\r' {
+				p[n] = b
+				n++
+				cr.state = stateNormal
+			}
+			// Otherwise, consume and discard
+
+		case stateBlockComment:
+			if b == '*' {
+				cr.state = stateMaybeBlockEnd
+			}
+			// Otherwise, consume and discard
+
+		case stateMaybeBlockEnd:
+			if b == '/' {
+				cr.state = stateNormal
+			} else if b == '*' {
+				// Stay in stateMaybeBlockEnd (consecutive *'s)
+				cr.state = stateMaybeBlockEnd
+			} else {
+				cr.state = stateBlockComment
+			}
+		}
+	}
+	return n, nil
+}
@@ -0,0 +1,164 @@
+package jsoncommentstrip_test
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/navidrome/navidrome/utils/jsoncommentstrip"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestJsonCommentStrip(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "JsonCommentStrip Suite")
+}
+
+var _ = Describe("NewReader", func() {
+	read := func(input string) string {
+		r := jsoncommentstrip.NewReader(strings.NewReader(input))
+		out, err := io.ReadAll(r)
+		Expect(err).ToNot(HaveOccurred())
+		return string(out)
+	}
+
+	// compact returns the compacted JSON form of s, for readable comparisons.
+	compact := func(s string) string {
+		var buf bytes.Buffer
+		ExpectWithOffset(1, json.Compact(&buf, []byte(s))).To(Succeed())
+		return buf.String()
+	}
+
+	It("passes through JSON without comments unchanged", func() {
+		input := `{"key": "value", "num": 42}`
+		Expect(read(input)).To(Equal(input))
+	})
+
+	It("strips single-line comments", func() {
+		input := `{
+			// this is a comment
+			"key": "value"
+		}`
+		Expect(compact(read(input))).To(Equal(compact(`{
+			"key": "value"
+		}`)))
+	})
+
+	It("strips single-line comments at end of line", func() {
+		input := `{
+			"key": "value" // inline comment
+		}`
+		Expect(compact(read(input))).To(Equal(compact(`{
+			"key": "value"
+		}`)))
+	})
+
+	It("strips block comments", func() {
+		input := `{/* comment */"key": "value"}`
+		Expect(compact(read(input))).To(Equal(`{"key":"value"}`))
+	})
+
+	It("strips multi-line block comments", func() {
+		input := `{
+			/* this is
+			a multi-line
+			comment */
+			"key": "value"
+		}`
+		Expect(compact(read(input))).To(Equal(compact(`{
+			"key": "value"
+		}`)))
+	})
+
+	It("preserves // inside JSON strings", func() {
+		input := `{"key": "value // not a comment"}`
+		Expect(read(input)).To(Equal(input))
+	})
+
+	It("preserves /* inside JSON strings", func() {
+		input := `{"key": "value /* not a comment */"}`
+		Expect(read(input)).To(Equal(input))
+	})
+
+	It("handles escaped quotes in strings", func() {
+		input := `{"key": "val\"ue // not a comment"}`
+		Expect(read(input)).To(Equal(input))
+	})
+
+	It("handles / at end of input as literal", func() {
+		input := `{"key": "value"}/`
+		Expect(read(input)).To(Equal(input))
+	})
+
+	It("handles * inside block comment not followed by /", func() {
+		input := `{/* a * b */"key": "value"}`
+		Expect(compact(read(input))).To(Equal(`{"key":"value"}`))
+	})
+
+	It("handles empty input", func() {
+		Expect(read("")).To(Equal(""))
+	})
+
+	It("handles mixed comments with real content", func() {
+		input := `{
+			// line comment
+			"name": "test", /* inline block */
+			/* multi
+			   line */
+			"value": "hello // world",
+			"other": 123 // trailing
+		}`
+		Expect(compact(read(input))).To(Equal(compact(`{
+			"name": "test",
+			"value": "hello // world",
+			"other": 123
+		}`)))
+	})
+
+	It("handles consecutive slashes that are not comments", func() {
+		input := `{"path": "/a/b"}`
+		Expect(read(input)).To(Equal(input))
+	})
+
+	It("handles block comment at end of input", func() {
+		input := `{"key": "value"}/* comment */`
+		Expect(compact(read(input))).To(Equal(`{"key":"value"}`))
+	})
+
+	It("strips comment with windows-style line endings", func() {
+		input := "{\r\n// comment\r\n\"key\": \"value\"\r\n}"
+		Expect(compact(read(input))).To(Equal(compact(`{"key": "value"}`)))
+	})
+
+	It("strips line comments with mixed line endings", func() {
+		// From original library: // comments with both \n and \r\n, including multiple on same line
+		input := "{\n\"one\": 1, // test //\n\"two\": 2, //test //\r\n\"string\": \"value\"\n//test\n}"
+		expected := "{\n\"one\": 1, \n\"two\": 2, \r\n\"string\": \"value\"\n\n}"
+		Expect(read(input)).To(Equal(expected))
+	})
+
+	It("strips line comment at start of JSON", func() {
+		// From original library: // comment as first thing in JSON
+		input := "{// woot\n\"one\": 1, // test //\n\"two\": 2, //test //\r\n\"string\": \"value\"\n//test\n}"
+		expected := "{\n\"one\": 1, \n\"two\": 2, \r\n\"string\": \"value\"\n\n}"
+		Expect(read(input)).To(Equal(expected))
+	})
+
+	It("strips block comments with mixed line endings inside", func() {
+		// From original library: block comment containing \r\n
+		input := "{/* multi\nline\r\ncomment */\"one\":1}"
+		expected := "{\"one\":1}"
+		Expect(read(input)).To(Equal(expected))
+	})
+
+	It("handles complex mix of escaped quotes, comments, and strings", func() {
+		// From original library TestQuotationEscape: escaped quote inside string followed by
+		// comment-like chars, then real comments of both types
+		input := "{/* multi\nline\r\ncomment */\"one\": \"a value \\\" // /*woot\"/* m\nl *///woot\r\n}"
+		expected := "{\"one\": \"a value \\\" // /*woot\"\r\n}"
+		Expect(read(input)).To(Equal(expected))
+	})
+})