Add fuzz tests for CPython Object API (object.go)

cpython/object_fuzz_test.go

@@ -0,0 +1,258 @@
+// MFP - Multi-Function Printers and scanners toolkit
+// CPython binding.
+//
+// Fuzz tests for Python Object operations and lifecycle.
+//
+//go:build linux || darwin || windows
+
+package cpython
+
+import (
+	"math"
+	"testing"
+)
+
+// FuzzObjectLifecycle stresses object creation, early invalidation and repeated Object allocation to exercise reference management.
+func FuzzObjectLifecycle(f *testing.F) {
+	f.Add(1)
+	f.Add(2)
+	f.Add(10)
+
+	f.Fuzz(func(t *testing.T, n int) {
+		if n < 0 {
+			return
+		}
+		if n > 20 {
+			n = 20
+		}
+
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		objs := make([]*Object, 0, n)
+		for i := 0; i < n; i++ {
+			obj := py.Eval("1")
+			_ = obj.Err()
+			objs = append(objs, obj)
+		}
+
+		// Invalidate some objects early
+		for i := 0; i < len(objs); i += 2 {
+			objs[i].Invalidate()
+		}
+
+	})
+}
+
+// FuzzObjectAttributes fuzzes GetAttr/SetAttr/DelAttr/HasAttr with random names
+func FuzzObjectAttributes(f *testing.F) {
+	f.Add("x")
+	f.Add("")
+	f.Add("__class__")
+	f.Add("does_not_exist")
+
+	f.Fuzz(func(t *testing.T, name string) {
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		obj := py.Eval(`{"a": 1}`)
+		if obj.Err() != nil {
+			return
+		}
+
+		// Attribute operations must never panic
+		_, _ = obj.HasAttr(name)
+		attr := obj.GetAttr(name)
+		_ = attr.Err()
+		_, _ = obj.DelAttr(name)
+		_ = obj.SetAttr(name, 1)
+	})
+}
+
+// FuzzObjectItems fuzzes Get/Set/Del/Contains on container objects
+func FuzzObjectItems(f *testing.F) {
+	f.Add(0)
+	f.Add(1)
+	f.Add(5)
+
+	f.Fuzz(func(t *testing.T, n int) {
+		if n < 0 {
+			return
+		}
+		if n > 20 {
+			n = 20
+		}
+
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		obj := py.Eval(`{}`)
+		if obj.Err() != nil {
+			return
+		}
+
+		// Insert values
+		for i := 0; i < n; i++ {
+			_ = obj.Set(i, i)
+		}
+
+		// Randomly query and delete
+		for i := 0; i < n; i++ {
+			_, _ = obj.Contains(i)
+			item := obj.Get(i)
+			_ = item.Err()
+			_, _ = obj.Del(i)
+			_, _ = obj.Del(i)
+		}
+	})
+}
+
+// FuzzObjectCall fuzzes calling objects as functions
+func FuzzObjectCall(f *testing.F) {
+	f.Add(1)
+	f.Add(2)
+	f.Add(10)
+
+	f.Fuzz(func(t *testing.T, n int) {
+		if n < 0 {
+			return
+		}
+		if n > 10 {
+			n = 10
+		}
+
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		fn := py.Eval("min")
+		if fn.Err() != nil {
+			return
+		}
+
+		for i := 0; i < n; i++ {
+			res := fn.Call(i, i+1)
+			_ = res.Err()
+
+			res = fn.CallKW(map[string]any{"default": i}, []int{})
+			_ = res.Err()
+		}
+	})
+}
+
+// FuzzObjectDecoders fuzzes type conversion accessors
+func FuzzObjectDecoders(f *testing.F) {
+	f.Add(int64(0))
+	f.Add(int64(-1))
+	f.Add(int64(1))
+	f.Add(int64(42))
+
+	f.Fuzz(func(t *testing.T, v int64) {
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		obj := py.NewObject(v)
+		if obj.Err() != nil {
+			return
+		}
+
+		_, _ = obj.Int()
+		_, _ = obj.Uint()
+		_, _ = obj.Float()
+		_, _ = obj.Complex()
+		_, _ = obj.Unicode()
+		_, _ = obj.Bytes()
+		_, _ = obj.Bool()
+	})
+}
+
+// FuzzObjectTypeChecks fuzzes Is* predicates
+func FuzzObjectTypeChecks(f *testing.F) {
+	f.Add("None")
+	f.Add("[]")
+	f.Add("{}")
+	f.Add("1")
+	f.Add("1.5")
+	f.Add("b'abc'")
+	f.Add("bytearray(b'abc')")
+	f.Add("min")
+
+	f.Fuzz(func(t *testing.T, expr string) {
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		obj := py.Eval(expr)
+		if obj.Err() != nil {
+			return
+		}
+
+		_ = obj.IsBool()
+		_ = obj.IsByteArray()
+		_ = obj.IsBytes()
+		_ = obj.IsCallable()
+		_ = obj.IsComplex()
+		_ = obj.IsDict()
+		_ = obj.IsFloat()
+		_ = obj.IsLong()
+		_ = obj.IsNone()
+		_ = obj.IsSeq()
+		_ = obj.IsUnicode()
+	})
+}
+
+// FuzzObjectReprStr fuzzes Str() and Repr() for stability
+func FuzzObjectReprStr(f *testing.F) {
+	f.Add("1")
+	f.Add("'hello'")
+	f.Add("[]")
+	f.Add("{}")
+
+	f.Fuzz(func(t *testing.T, expr string) {
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		obj := py.Eval(expr)
+		if obj.Err() != nil {
+			return
+		}
+
+		_, _ = obj.Str()
+		_, _ = obj.Repr()
+	})
+}
+
+// FuzzObjectNumericEdgeCases fuzzes numeric edge cases that often break bindings
+func FuzzObjectNumericEdgeCases(f *testing.F) {
+	f.Add(float64(0))
+	f.Add(float64(math.MaxFloat64))
+	f.Add(float64(math.SmallestNonzeroFloat64))
+
+	f.Fuzz(func(t *testing.T, v float64) {
+		py := getFuzzPython(t)
+		if py == nil {
+			return
+		}
+
+		obj := py.NewObject(v)
+		if obj.Err() != nil {
+			return
+		}
+
+		_, _ = obj.Float()
+		_, _ = obj.Int()
+		_, _ = obj.Uint()
+	})
+}