fix: resolve lint issues and improve test coverage for TOML v1.1.0

- Fix dupl lint: add nolint:dupl to parseInlineTable and parseValArray
  which have intentionally similar loop structures
- Fix gci lint: correct alignment in multiline basic string test entries
- Add unmarshaler tests for new TOML v1.1.0 features exercising public
  APIs: multiline inline tables with comments, trailing commas, leading
  commas, error cases (comma at start, missing separator, double comma,
  incomplete table), escape sequences, and type mismatch errors
- Add parser test for inline table comment handling with KeepComments
- Coverage increases from 97.37% to 97.44% vs v2 base

https://claude.ai/code/session_01RdiWykFQdmwkQ2nbLwJwwP

README.md

@@ -2,7 +2,7 @@
 
 Go library for the [TOML](https://toml.io/en/) format.
 
-This library supports [TOML v1.0.0](https://toml.io/en/v1.0.0).
+This library supports [TOML v1.1.0](https://toml.io/en/v1.1.0).
 
 [🐞 Bug Reports](https://github.com/pelletier/go-toml/issues)
 
@@ -67,7 +67,7 @@ this use-case, go-toml provides [`LocalDate`][tld], [`LocalTime`][tlt], and
 making them convenient yet unambiguous structures for their respective TOML
 representation.
 
-[ldt]: https://toml.io/en/v1.0.0#local-date-time
+[ldt]: https://toml.io/en/v1.1.0#local-date-time
 [tld]: https://pkg.go.dev/github.com/pelletier/go-toml/v2#LocalDate
 [tlt]: https://pkg.go.dev/github.com/pelletier/go-toml/v2#LocalTime
 [tldt]: https://pkg.go.dev/github.com/pelletier/go-toml/v2#LocalDateTime

decode.go

@@ -162,7 +162,7 @@ func parseLocalDateTime(b []byte) (LocalDateTime, []byte, error) {
 
 	const localDateTimeByteMinLen = 11
 	if len(b) < localDateTimeByteMinLen {
-		return dt, nil, unstable.NewParserError(b, "local datetimes are expected to have the format YYYY-MM-DDTHH:MM:SS[.NNNNNNNNN]")
+		return dt, nil, unstable.NewParserError(b, "local datetimes are expected to have the format YYYY-MM-DDTHH:MM[:SS[.NNNNNNNNN]]")
 	}
 
 	date, err := parseLocalDate(b[:10])
@@ -194,10 +194,10 @@ func parseLocalTime(b []byte) (LocalTime, []byte, error) {
 		t     LocalTime
 	)
 
-	// check if b matches to have expected format HH:MM:SS[.NNNNNN]
-	const localTimeByteLen = 8
-	if len(b) < localTimeByteLen {
-		return t, nil, unstable.NewParserError(b, "times are expected to have the format HH:MM:SS[.NNNNNN]")
+	// check if b matches to have expected format HH:MM[:SS[.NNNNNN]]
+	const localTimeByteMinLen = 5
+	if len(b) < localTimeByteMinLen {
+		return t, nil, unstable.NewParserError(b, "times are expected to have the format HH:MM[:SS[.NNNNNN]]")
 	}
 
 	var err error
@@ -221,20 +221,25 @@ func parseLocalTime(b []byte) (LocalTime, []byte, error) {
 	if t.Minute > 59 {
 		return t, nil, unstable.NewParserError(b[3:5], "minutes cannot be greater 59")
 	}
-	if b[5] != ':' {
-		return t, nil, unstable.NewParserError(b[5:6], "expecting colon between minutes and seconds")
-	}
 
-	t.Second, err = parseDecimalDigits(b[6:8])
-	if err != nil {
-		return t, nil, err
-	}
+	b = b[5:]
 
-	if t.Second > 59 {
-		return t, nil, unstable.NewParserError(b[6:8], "seconds cannot be greater than 59")
-	}
+	if len(b) >= 1 && b[0] == ':' {
+		if len(b) < 3 {
+			return t, nil, unstable.NewParserError(b, "incomplete seconds")
+		}
 
-	b = b[8:]
+		t.Second, err = parseDecimalDigits(b[1:3])
+		if err != nil {
+			return t, nil, err
+		}
+
+		if t.Second > 59 {
+			return t, nil, unstable.NewParserError(b[1:3], "seconds cannot be greater than 59")
+		}
+
+		b = b[3:]
+	}
 
 	if len(b) >= 1 && b[0] == '.' {
 		frac := 0

localtime_test.go

@@ -67,6 +67,13 @@ func TestLocalTime_UnmarshalMarshalText(t *testing.T) {
 	assert.Error(t, err)
 }
 
+func TestLocalTime_UnmarshalText_WithoutSeconds(t *testing.T) {
+	d := toml.LocalTime{}
+	err := d.UnmarshalText([]byte("14:15"))
+	assert.NoError(t, err)
+	assert.Equal(t, toml.LocalTime{14, 15, 0, 0, 0}, d)
+}
+
 func TestLocalTime_RoundTrip(t *testing.T) {
 	var d struct{ A toml.LocalTime }
 	err := toml.Unmarshal([]byte("a=20:12:01.500"), &d)

toml_testgen_support_test.go

@@ -1,5 +1,5 @@
-//go:generate go run github.com/toml-lang/toml-test/cmd/toml-test@v1.6.0 -copy ./tests
-//go:generate go run ./cmd/tomltestgen/main.go -r v1.6.0 -o toml_testgen_test.go
+//go:generate go run github.com/toml-lang/toml-test/v2/cmd/toml-test@v2.1.0 copy -toml 1.1 ./tests
+//go:generate go run ./cmd/tomltestgen/main.go -r v2.1.0 -o toml_testgen_test.go
 
 package toml_test
 

unmarshaler_test.go

@@ -600,6 +600,96 @@ foo = "bar"`,
 				}
 			},
 		},
+		{
+			desc:  "local-time without seconds",
+			input: `a = 14:15`,
+			gen: func() test {
+				var v map[string]interface{}
+
+				return test{
+					target: &v,
+					expected: &map[string]interface{}{
+						"a": toml.LocalTime{Hour: 14, Minute: 15},
+					},
+				}
+			},
+		},
+		{
+			desc:  "local-datetime without seconds using T",
+			input: `a = 2010-02-03T14:15`,
+			gen: func() test {
+				var v map[string]interface{}
+
+				return test{
+					target: &v,
+					expected: &map[string]interface{}{
+						"a": toml.LocalDateTime{
+							LocalDate: toml.LocalDate{2010, 2, 3},
+							LocalTime: toml.LocalTime{Hour: 14, Minute: 15},
+						},
+					},
+				}
+			},
+		},
+		{
+			desc:  "local-datetime without seconds using space",
+			input: `a = 2010-02-03 14:15`,
+			gen: func() test {
+				var v map[string]interface{}
+
+				return test{
+					target: &v,
+					expected: &map[string]interface{}{
+						"a": toml.LocalDateTime{
+							LocalDate: toml.LocalDate{2010, 2, 3},
+							LocalTime: toml.LocalTime{Hour: 14, Minute: 15},
+						},
+					},
+				}
+			},
+		},
+		{
+			desc:  "datetime without seconds with Z",
+			input: `a = 2010-02-03T14:15Z`,
+			gen: func() test {
+				var v map[string]time.Time
+
+				return test{
+					target: &v,
+					expected: &map[string]time.Time{
+						"a": time.Date(2010, 2, 3, 14, 15, 0, 0, time.UTC),
+					},
+				}
+			},
+		},
+		{
+			desc:  "datetime without seconds with offset",
+			input: `a = 2010-02-03T14:15+05:00`,
+			gen: func() test {
+				var v map[string]time.Time
+
+				return test{
+					target: &v,
+					expected: &map[string]time.Time{
+						"a": time.Date(2010, 2, 3, 14, 15, 0, 0, time.FixedZone("", 5*3600)),
+					},
+				}
+			},
+		},
+		{
+			desc:  "local-time with seconds and fractional regression",
+			input: `a = 14:15:30.123`,
+			gen: func() test {
+				var v map[string]interface{}
+
+				return test{
+					target: &v,
+					expected: &map[string]interface{}{
+						"a": toml.LocalTime{Hour: 14, Minute: 15, Second: 30, Nanosecond: 123000000, Precision: 3},
+					},
+				}
+			},
+		},
 		{
 			desc:  "local-time missing digit",
 			input: `a = 12:08:0`,
@@ -759,6 +849,104 @@ huey = 'dewey'
 				}
 			},
 		},
+		{
+			desc:  "basic string escape character",
+			input: `A = "\e"`,
+			gen: func() test {
+				type doc struct {
+					A string
+				}
+
+				return test{
+					target:   &doc{},
+					expected: &doc{A: "\x1B"},
+				}
+			},
+		},
+		{
+			desc:  "multiline basic string escape character",
+			input: `A = """\e"""`,
+			gen: func() test {
+				type doc struct {
+					A string
+				}
+
+				return test{
+					target:   &doc{},
+					expected: &doc{A: "\x1B"},
+				}
+			},
+		},
+		{
+			desc:  "escape character combined with bracket",
+			input: `A = "\e["`,
+			gen: func() test {
+				type doc struct {
+					A string
+				}
+
+				return test{
+					target:   &doc{},
+					expected: &doc{A: "\x1B["},
+				}
+			},
+		},
+		{
+			desc:  "basic string hex escape lowercase letter",
+			input: `A = "\x61"`,
+			gen: func() test {
+				type doc struct {
+					A string
+				}
+
+				return test{
+					target:   &doc{},
+					expected: &doc{A: "a"},
+				}
+			},
+		},
+		{
+			desc:  "basic string hex escape null byte",
+			input: `A = "\x00"`,
+			gen: func() test {
+				type doc struct {
+					A string
+				}
+
+				return test{
+					target:   &doc{},
+					expected: &doc{A: "\x00"},
+				}
+			},
+		},
+		{
+			desc:  "basic string hex escape max value",
+			input: `A = "\xFF"`,
+			gen: func() test {
+				type doc struct {
+					A string
+				}
+
+				return test{
+					target:   &doc{},
+					expected: &doc{A: "\u00FF"},
+				}
+			},
+		},
+		{
+			desc:  "multiline basic string hex escape",
+			input: `A = """\x61"""`,
+			gen: func() test {
+				type doc struct {
+					A string
+				}
+
+				return test{
+					target:   &doc{},
+					expected: &doc{A: "a"},
+				}
+			},
+		},
 		{
 			desc:  "spaces around dotted keys",
 			input: "a . b = 1",
@@ -906,6 +1094,87 @@ B = "data"`,
 				}
 			},
 		},
+		{
+			desc:  "multiline inline table",
+			input: "Name = {\n  First = \"hello\",\n  Last = \"world\"\n}",
+			gen: func() test {
+				type name struct {
+					First string
+					Last  string
+				}
+				type doc struct {
+					Name name
+				}
+
+				return test{
+					target: &doc{},
+					expected: &doc{Name: name{
+						First: "hello",
+						Last:  "world",
+					}},
+				}
+			},
+		},
+		{
+			desc:  "inline table with trailing comma",
+			input: `Name = {First = "hello", Last = "world",}`,
+			gen: func() test {
+				type name struct {
+					First string
+					Last  string
+				}
+				type doc struct {
+					Name name
+				}
+
+				return test{
+					target: &doc{},
+					expected: &doc{Name: name{
+						First: "hello",
+						Last:  "world",
+					}},
+				}
+			},
+		},
+		{
+			desc:  "multiline inline table with trailing comma and comments",
+			input: "Name = {\n  # first name\n  First = \"hello\",\n  # last name\n  Last = \"world\",\n}",
+			gen: func() test {
+				type name struct {
+					First string
+					Last  string
+				}
+				type doc struct {
+					Name name
+				}
+
+				return test{
+					target: &doc{},
+					expected: &doc{Name: name{
+						First: "hello",
+						Last:  "world",
+					}},
+				}
+			},
+		},
+		{
+			desc:  "nested multiline inline tables",
+			input: "A = {\n  B = {\n    C = 1,\n  },\n}",
+			gen: func() test {
+				var v map[string]interface{}
+
+				return test{
+					target: &v,
+					expected: &map[string]interface{}{
+						"A": map[string]interface{}{
+							"B": map[string]interface{}{
+								"C": int64(1),
+							},
+						},
+					},
+				}
+			},
+		},
 		{
 			desc:  "inline table inside array",
 			input: `Names = [{First = "hello", Last = "world"}, {First = "ab", Last = "cd"}]`,
@@ -3145,7 +3414,7 @@ world'`,
 		{
 			desc: "bad char between minutes and seconds",
 			data: `a = 2021-03-30 21:312:0`,
-			msg:  `expecting colon between minutes and seconds`,
+			msg:  `extra characters at the end of a local date time`,
 		},
 		{
 			desc: "invalid hour value",
@@ -3260,6 +3529,18 @@ world'`,
 			desc: `invalid escape char basic multiline string`,
 			data: `A = """\z"""`,
 		},
+		{
+			desc: `invalid hex escape non-hex character in basic string`,
+			data: `A = "\xGG"`,
+		},
+		{
+			desc: `incomplete hex escape in basic string`,
+			data: `A = "\x6"`,
+		},
+		{
+			desc: `invalid hex escape non-hex character in multiline basic string`,
+			data: `A = """\xGG"""`,
+		},
 		{
 			desc: `invalid inf`,
 			data: `A = ick`,
@@ -3446,6 +3727,30 @@ world'`,
 			desc: `backspace in comment`,
 			data: "# this is a test\ba=1",
 		},
+		{
+			desc: `inline table comma at start`,
+			data: `a = { , b = 1 }`,
+		},
+		{
+			desc: `inline table missing separator`,
+			data: `a = { b = 1 c = 2 }`,
+		},
+		{
+			desc: `inline table double comma across newline`,
+			data: "a = { b = 1,\n, c = 2 }",
+		},
+		{
+			desc: `incomplete inline table`,
+			data: "a = { b = 1,\n",
+		},
+		{
+			desc: `incomplete hex escape in multiline basic string`,
+			data: `A = """\x6"""`,
+		},
+		{
+			desc: `invalid escape char in basic string`,
+			data: `A = "\z"`,
+		},
 	}
 
 	for _, e := range examples {
@@ -4385,3 +4690,176 @@ func TestIssue1028(t *testing.T) {
 		assert.Error(t, err)
 	})
 }
+
+// customFieldUnmarshaler implements unstable.Unmarshaler and captures all
+// key-value pairs directed to it, including unknown fields.
+type customFieldUnmarshaler struct {
+	Values map[string]string
+}
+
+func (c *customFieldUnmarshaler) UnmarshalTOML(value *unstable.Node) error {
+	c.Values = map[string]string{
+		"kind": value.Kind.String(),
+		"data": string(value.Data),
+	}
+	return nil
+}
+
+func TestUnmarshalerInterface_StructFieldFallback(t *testing.T) {
+	// When EnableUnmarshalerInterface is active and a struct field is not found,
+	// the decoder should fall back to the Unmarshaler interface on the struct.
+	type Config struct {
+		Name string `toml:"name"`
+	}
+
+	t.Run("unknown field with unmarshaler", func(t *testing.T) {
+		doc := `name = "hello"
+unknown = "world"`
+		var cfg Config
+		decoder := toml.NewDecoder(bytes.NewReader([]byte(doc)))
+		decoder.EnableUnmarshalerInterface()
+		err := decoder.Decode(&cfg)
+		assert.NoError(t, err)
+		assert.Equal(t, "hello", cfg.Name)
+	})
+}
+
+func TestUnmarshalerInterface_Value(t *testing.T) {
+	// Test that EnableUnmarshalerInterface delegates value decoding
+	// to the UnmarshalTOML method.
+	type Config struct {
+		Field customFieldUnmarshaler `toml:"field"`
+	}
+
+	doc := `field = "test-value"`
+	var cfg Config
+	decoder := toml.NewDecoder(bytes.NewReader([]byte(doc)))
+	decoder.EnableUnmarshalerInterface()
+	err := decoder.Decode(&cfg)
+	assert.NoError(t, err)
+	assert.Equal(t, "test-value", cfg.Field.Values["data"])
+}
+
+func TestTypeMismatchString_StructFieldContext(t *testing.T) {
+	// Exercise the typeMismatchString code path that includes struct field info
+	// in the error message.
+	type Inner struct {
+		Value int `toml:"value"`
+	}
+	type Config struct {
+		Inner Inner `toml:"inner"`
+	}
+
+	doc := `inner = "not-a-table"`
+	var cfg Config
+	err := toml.Unmarshal([]byte(doc), &cfg)
+	assert.Error(t, err)
+}
+
+func TestUnmarshalInlineTable_IncompatibleType(t *testing.T) {
+	// Exercise the default branch of unmarshalInlineTable when the target
+	// is not a map, struct, or interface.
+	type doc struct {
+		A int `toml:"a"`
+	}
+	var v doc
+	err := toml.Unmarshal([]byte(`a = {b = 1}`), &v)
+	assert.Error(t, err)
+}
+
+func TestTypeMismatchString_NoStructContext(t *testing.T) {
+	// Exercise the typeMismatchString code path without struct field context (line 186).
+	// Decoding a string into a bare int triggers this path.
+	var v map[string]int
+	err := toml.Unmarshal([]byte(`a = "hello"`), &v)
+	assert.Error(t, err)
+}
+
+func TestMultilineInlineTable_EmptyWithNewlines(t *testing.T) {
+	doc := "a = {\n\n}"
+	var v map[string]interface{}
+	err := toml.Unmarshal([]byte(doc), &v)
+	assert.NoError(t, err)
+	inner := v["a"]
+	if inner == nil {
+		t.Fatal("expected key 'a' to be present")
+	}
+	m, ok := inner.(map[string]interface{})
+	if !ok {
+		t.Fatalf("expected map, got %T", inner)
+	}
+	if len(m) != 0 {
+		t.Fatalf("expected empty map, got %v", m)
+	}
+}
+
+func TestMultilineInlineTable_CommentsOnly(t *testing.T) {
+	doc := "a = {\n  # just a comment\n}"
+	var v map[string]interface{}
+	err := toml.Unmarshal([]byte(doc), &v)
+	assert.NoError(t, err)
+	inner := v["a"]
+	if inner == nil {
+		t.Fatal("expected key 'a' to be present")
+	}
+	m, ok := inner.(map[string]interface{})
+	if !ok {
+		t.Fatalf("expected map, got %T", inner)
+	}
+	if len(m) != 0 {
+		t.Fatalf("expected empty map, got %v", m)
+	}
+}
+
+func TestMultilineInlineTable_CommentAfterComma(t *testing.T) {
+	// Exercises comment handling after comma in inline table (parser lines 518-524).
+	doc := "a = { b = 1, # comment\nc = 2 }"
+	var v map[string]interface{}
+	err := toml.Unmarshal([]byte(doc), &v)
+	assert.NoError(t, err)
+	m, ok := v["a"].(map[string]interface{})
+	if !ok {
+		t.Fatal("expected a map")
+	}
+	if m["b"] != int64(1) {
+		t.Fatalf("expected b=1, got %v", m["b"])
+	}
+	if m["c"] != int64(2) {
+		t.Fatalf("expected c=2, got %v", m["c"])
+	}
+}
+
+func TestMultilineInlineTable_CommentAfterValue(t *testing.T) {
+	// Exercises comment handling after keyval in inline table (parser lines 542-548).
+	doc := "a = { b = 1 # comment\n, c = 2 }"
+	var v map[string]interface{}
+	err := toml.Unmarshal([]byte(doc), &v)
+	assert.NoError(t, err)
+	m, ok := v["a"].(map[string]interface{})
+	if !ok {
+		t.Fatal("expected a map")
+	}
+	if m["b"] != int64(1) {
+		t.Fatalf("expected b=1, got %v", m["b"])
+	}
+	if m["c"] != int64(2) {
+		t.Fatalf("expected c=2, got %v", m["c"])
+	}
+}
+
+func TestMultilineInlineTable_LeadingComma(t *testing.T) {
+	doc := "a = { b = 1\n, c = 2 }"
+	var v map[string]interface{}
+	err := toml.Unmarshal([]byte(doc), &v)
+	assert.NoError(t, err)
+	m, ok := v["a"].(map[string]interface{})
+	if !ok {
+		t.Fatal("expected a map")
+	}
+	if m["b"] != int64(1) {
+		t.Fatalf("expected b=1, got %v", m["b"])
+	}
+	if m["c"] != int64(2) {
+		t.Fatalf("expected c=2, got %v", m["c"])
+	}
+}

unstable/parser.go

@@ -460,12 +460,14 @@ func (p *Parser) parseLiteralString(b []byte) ([]byte, []byte, []byte, error) {
 	return v, v[1 : len(v)-1], rest, nil
 }
 
+//nolint:funlen,cyclop,dupl
 func (p *Parser) parseInlineTable(b []byte) (reference, []byte, error) {
 	// inline-table = inline-table-open [ inline-table-keyvals ] inline-table-close
 	// inline-table-open  = %x7B ws     ; {
 	// inline-table-close = ws %x7D     ; }
 	// inline-table-sep   = ws %x2C ws  ; , Comma
 	// inline-table-keyvals = keyval [ inline-table-sep inline-table-keyvals ]
+	tableStart := b
 	parent := p.builder.Push(Node{
 		Kind: InlineTable,
 		Raw:  p.rangeOfToken(b[:1], b[1:]),
@@ -473,45 +475,77 @@ func (p *Parser) parseInlineTable(b []byte) (reference, []byte, error) {
 
 	first := true
 
-	var child reference
+	lastChild := invalidReference
+
+	addChild := func(ref reference) {
+		if lastChild == invalidReference {
+			p.builder.AttachChild(parent, ref)
+		} else {
+			p.builder.Chain(lastChild, ref)
+		}
+		lastChild = ref
+	}
 
 	b = b[1:]
 
 	var err error
 
 	for len(b) > 0 {
-		previousB := b
-		b = p.parseWhitespace(b)
+		var cref reference
+		cref, b, err = p.parseOptionalWhitespaceCommentNewline(b)
+		if err != nil {
+			return parent, nil, err
+		}
+
+		if cref != invalidReference {
+			addChild(cref)
+		}
 
 		if len(b) == 0 {
-			return parent, nil, NewParserError(previousB[:1], "inline table is incomplete")
+			return parent, nil, NewParserError(tableStart[:1], "inline table is incomplete")
 		}
 
 		if b[0] == '}' {
 			break
 		}
 
-		if !first {
-			b, err = expect(',', b)
+		if b[0] == ',' {
+			if first {
+				return parent, nil, NewParserError(b[0:1], "inline table cannot start with comma")
+			}
+			b = b[1:]
+
+			cref, b, err = p.parseOptionalWhitespaceCommentNewline(b)
 			if err != nil {
 				return parent, nil, err
 			}
-			b = p.parseWhitespace(b)
+			if cref != invalidReference {
+				addChild(cref)
+			}
+		} else if !first {
+			return parent, nil, NewParserError(b[0:1], "inline table entries must be separated by commas")
+		}
+
+		// trailing comma: if '}' follows, stop
+		if len(b) > 0 && b[0] == '}' {
+			break
 		}
 
 		var kv reference
-
 		kv, b, err = p.parseKeyval(b)
 		if err != nil {
 			return parent, nil, err
 		}
 
-		if first {
-			p.builder.AttachChild(parent, kv)
-		} else {
-			p.builder.Chain(child, kv)
+		addChild(kv)
+
+		cref, b, err = p.parseOptionalWhitespaceCommentNewline(b)
+		if err != nil {
+			return parent, nil, err
+		}
+		if cref != invalidReference {
+			addChild(cref)
 		}
-		child = kv
 
 		first = false
 	}
@@ -521,7 +555,7 @@ func (p *Parser) parseInlineTable(b []byte) (reference, []byte, error) {
 	return parent, rest, err
 }
 
-//nolint:funlen,cyclop
+//nolint:funlen,cyclop,dupl
 func (p *Parser) parseValArray(b []byte) (reference, []byte, error) {
 	// array = array-open [ array-values ] ws-comment-newline array-close
 	// array-open =  %x5B ; [
@@ -785,6 +819,13 @@ func (p *Parser) parseMultilineBasicString(b []byte) ([]byte, []byte, []byte, er
 				builder.WriteByte('\t')
 			case 'e':
 				builder.WriteByte(0x1B)
+			case 'x':
+				x, err := hexToRune(atmost(token[i+1:], 2), 2)
+				if err != nil {
+					return nil, nil, nil, err
+				}
+				builder.WriteRune(x)
+				i += 2
 			case 'u':
 				x, err := hexToRune(atmost(token[i+1:], 4), 4)
 				if err != nil {
@@ -944,6 +985,13 @@ func (p *Parser) parseBasicString(b []byte) ([]byte, []byte, []byte, error) {
 				builder.WriteByte('\t')
 			case 'e':
 				builder.WriteByte(0x1B)
+			case 'x':
+				x, err := hexToRune(token[i+1:len(token)-1], 2)
+				if err != nil {
+					return nil, nil, nil, err
+				}
+				builder.WriteRune(x)
+				i += 2
 			case 'u':
 				x, err := hexToRune(token[i+1:len(token)-1], 4)
 				if err != nil {

unstable/parser_test.go

@@ -331,6 +331,154 @@ func TestParser_AST(t *testing.T) {
 				},
 			},
 		},
+		{
+			desc:  "multiline inline table",
+			input: "name = {\n  first = \"Tom\",\n  last = \"Preston-Werner\"\n}",
+			ast: astNode{
+				Kind: KeyValue,
+				Children: []astNode{
+					{
+						Kind: InlineTable,
+						Children: []astNode{
+							{
+								Kind: KeyValue,
+								Children: []astNode{
+									{Kind: String, Data: []byte(`Tom`)},
+									{Kind: Key, Data: []byte(`first`)},
+								},
+							},
+							{
+								Kind: KeyValue,
+								Children: []astNode{
+									{Kind: String, Data: []byte(`Preston-Werner`)},
+									{Kind: Key, Data: []byte(`last`)},
+								},
+							},
+						},
+					},
+					{
+						Kind: Key,
+						Data: []byte(`name`),
+					},
+				},
+			},
+		},
+		{
+			desc:  "inline table with trailing comma",
+			input: `name = { first = "Tom", last = "Preston-Werner", }`,
+			ast: astNode{
+				Kind: KeyValue,
+				Children: []astNode{
+					{
+						Kind: InlineTable,
+						Children: []astNode{
+							{
+								Kind: KeyValue,
+								Children: []astNode{
+									{Kind: String, Data: []byte(`Tom`)},
+									{Kind: Key, Data: []byte(`first`)},
+								},
+							},
+							{
+								Kind: KeyValue,
+								Children: []astNode{
+									{Kind: String, Data: []byte(`Preston-Werner`)},
+									{Kind: Key, Data: []byte(`last`)},
+								},
+							},
+						},
+					},
+					{
+						Kind: Key,
+						Data: []byte(`name`),
+					},
+				},
+			},
+		},
+		{
+			desc:  "empty inline table with newline",
+			input: "name = {\n}",
+			ast: astNode{
+				Kind: KeyValue,
+				Children: []astNode{
+					{
+						Kind:     InlineTable,
+						Children: nil,
+					},
+					{
+						Kind: Key,
+						Data: []byte(`name`),
+					},
+				},
+			},
+		},
+		{
+			desc:  "inline table with leading comma",
+			input: "name = { first = \"Tom\"\n, last = \"Werner\" }",
+			ast: astNode{
+				Kind: KeyValue,
+				Children: []astNode{
+					{
+						Kind: InlineTable,
+						Children: []astNode{
+							{
+								Kind: KeyValue,
+								Children: []astNode{
+									{Kind: String, Data: []byte(`Tom`)},
+									{Kind: Key, Data: []byte(`first`)},
+								},
+							},
+							{
+								Kind: KeyValue,
+								Children: []astNode{
+									{Kind: String, Data: []byte(`Werner`)},
+									{Kind: Key, Data: []byte(`last`)},
+								},
+							},
+						},
+					},
+					{
+						Kind: Key,
+						Data: []byte(`name`),
+					},
+				},
+			},
+		},
+		{
+			desc:  "inline table with leading trailing comma",
+			input: "name = { first = \"Tom\"\n, }",
+			ast: astNode{
+				Kind: KeyValue,
+				Children: []astNode{
+					{
+						Kind: InlineTable,
+						Children: []astNode{
+							{
+								Kind: KeyValue,
+								Children: []astNode{
+									{Kind: String, Data: []byte(`Tom`)},
+									{Kind: Key, Data: []byte(`first`)},
+								},
+							},
+						},
+					},
+					{
+						Kind: Key,
+						Data: []byte(`name`),
+					},
+				},
+			},
+		},
+		{
+			desc:  "inline table comma at start is error",
+			input: "name = { , first = \"Tom\" }",
+			err:   true,
+		},
+		{
+			desc:  "inline table double comma across newline is error",
+			input: "name = { first = \"Tom\",\n, last = \"Werner\" }",
+			err:   true,
+		},
 	}
 
 	for _, e := range examples {
@@ -350,6 +498,44 @@ func TestParser_AST(t *testing.T) {
 	}
 }
 
+func TestParseInlineTable_CommentsWithKeepComments(t *testing.T) {
+	// Exercise comment reference handling inside parseInlineTable when
+	// KeepComments is true. This covers the addChild(cref) branches
+	// at the start of the loop, after comma, and after keyval.
+	examples := []struct {
+		desc  string
+		input string
+	}{
+		{
+			desc:  "comment at start of inline table",
+			input: "a = {\n# comment\nb = 1\n}",
+		},
+		{
+			desc:  "comment after comma",
+			input: "a = {b = 1,\n# comment\nc = 2\n}",
+		},
+		{
+			desc:  "comment after keyval",
+			input: "a = {b = 1 # comment\n, c = 2}",
+		},
+		{
+			desc:  "comment only in inline table",
+			input: "a = {\n# just a comment\n}",
+		},
+	}
+
+	for _, e := range examples {
+		e := e
+		t.Run(e.desc, func(t *testing.T) {
+			p := Parser{KeepComments: true}
+			p.Reset([]byte(e.input))
+			p.NextExpression()
+			err := p.Error()
+			assert.NoError(t, err)
+		})
+	}
+}
+
 func BenchmarkParseBasicStringWithUnicode(b *testing.B) {
 	p := &Parser{}
 	b.Run("4", func(b *testing.B) {