v0.1.0 initial commit

fuzz_test.go

@@ -0,0 +1,87 @@
+package toml
+
+import (
+	"reflect"
+	"testing"
+	"unicode/utf8"
+)
+
+func FuzzParse(f *testing.F) {
+	for _, s := range []string{
+		"",
+		`key = "value"`,
+		"[table]\nk = 1",
+		"[[arr]]\nx = 1.5\n[[arr]]\nx = 2e3",
+		"t = { a = 1, b = { c = [1, 2] } }",
+		`s = "esc \u00E9 \t"`,
+		"n = -0x10\nb = 0b101\no = 0o17",
+	} {
+		f.Add([]byte(s))
+	}
+	f.Fuzz(func(t *testing.T, data []byte) {
+		p := NewParser(data)
+		_, _ = p.Parse() // property: no panic, no hang
+	})
+}
+
+// normalize collapses the parser's dual slice representations
+// ([]map[string]any for [[headers]], []any for inline arrays) so the
+// fixpoint compares values, not construction syntax.
+func normalize(v any) any {
+	switch t := v.(type) {
+	case map[string]any:
+		for k, vv := range t {
+			t[k] = normalize(vv)
+		}
+		return t
+	case []map[string]any:
+		out := make([]any, len(t))
+		for i, m := range t {
+			out[i] = normalize(m)
+		}
+		return out
+	case []any:
+		for i, vv := range t {
+			t[i] = normalize(vv)
+		}
+		return t
+	}
+	return v
+}
+
+func FuzzRoundTrip(f *testing.F) {
+	for _, s := range []string{
+		"a = 1\nb = 2.5\nc = true\nd = \"x\"",
+		"[t]\nk = [1, 2, 3]",
+		"[[s]]\nn = \"a\"\n[[s]]\nn = \"b\"",
+		`m = { x = 1, y = { z = "q" } }`,
+		`u = "日本語 \u00E9"`,
+		"big = 1e100\nsmall = 1e-100",
+	} {
+		f.Add([]byte(s))
+	}
+	f.Fuzz(func(t *testing.T, data []byte) {
+		// Encoder normalizes invalid UTF-8 to U+FFFD (WriteRune); byte-exact
+		// round trip is only a property of valid input.
+		if !utf8.Valid(data) {
+			t.Skip()
+		}
+		m1, err := NewParser(data).Parse()
+		if err != nil {
+			t.Skip()
+		}
+		out, err := Marshal(m1)
+		if err != nil {
+			// Parser accepts values the encoder cannot represent
+			// (mixed table/scalar arrays). Documented asymmetry.
+			t.Skip()
+		}
+		m2, err := NewParser(out).Parse()
+		if err != nil {
+			t.Fatalf("emitted TOML failed to re-parse: %v\nemitted:\n%s", err, out)
+		}
+		if !reflect.DeepEqual(normalize(m1), normalize(m2)) {
+			t.Fatalf("fixpoint violation:\nm1: %#v\nm2: %#v\nemitted:\n%s", m1, m2, out)
+		}
+	})
+}