Merge pull request #3087 from nspcc-dev/smart-binding

rpcbinding: export any unexported fields of structures/events

cli/smartcontract/generate_test.go

@@ -437,12 +437,12 @@ func TestAssistedRPCBindings(t *testing.T) {
 	}
 
 	for _, hasDefinedHash := range []bool{true, false} {
-		checkBinding(filepath.Join("testdata", "types"), hasDefinedHash, false)
+		checkBinding(filepath.Join("testdata", "rpcbindings", "types"), hasDefinedHash, false)
-		checkBinding(filepath.Join("testdata", "structs"), hasDefinedHash, false)
+		checkBinding(filepath.Join("testdata", "rpcbindings", "structs"), hasDefinedHash, false)
 	}
-	checkBinding(filepath.Join("testdata", "notifications"), true, false)
+	checkBinding(filepath.Join("testdata", "rpcbindings", "notifications"), true, false)
-	checkBinding(filepath.Join("testdata", "notifications"), true, false, "_extended")
+	checkBinding(filepath.Join("testdata", "rpcbindings", "notifications"), true, false, "_extended")
-	checkBinding(filepath.Join("testdata", "notifications"), true, true, "_guessed")
+	checkBinding(filepath.Join("testdata", "rpcbindings", "notifications"), true, true, "_guessed")
 
 	require.False(t, rewriteExpectedOutputs)
 }
@@ -540,10 +540,10 @@ func TestCompile_GuessEventTypes(t *testing.T) {
 	}
 
 	t.Run("not declared in manifest", func(t *testing.T) {
-		check(t, filepath.Join("testdata", "invalid5"), "inconsistent usages of event `Non declared event`: not declared in the contract config")
+		check(t, filepath.Join("testdata", "rpcbindings", "invalid1"), "inconsistent usages of event `Non declared event`: not declared in the contract config")
 	})
 	t.Run("invalid number of params", func(t *testing.T) {
-		check(t, filepath.Join("testdata", "invalid6"), "inconsistent usages of event `SomeEvent` against config: number of params mismatch: 2 vs 1")
+		check(t, filepath.Join("testdata", "rpcbindings", "invalid2"), "inconsistent usages of event `SomeEvent` against config: number of params mismatch: 2 vs 1")
 	})
 	/*
 		// TODO: this on is a controversial one. If event information is provided in the config file, then conversion code
@@ -552,13 +552,61 @@ func TestCompile_GuessEventTypes(t *testing.T) {
 		// Thus, this testcase is always failing (no compilation error occures).
 		// Question: do we want to compare `RealType` of the emitted parameter with the one expected in the manifest?
 		t.Run("SC parameter type mismatch", func(t *testing.T) {
-			check(t, filepath.Join("testdata", "invalid7"), "inconsistent usages of event `SomeEvent` against config: number of params mismatch: 2 vs 1")
+			check(t, filepath.Join("testdata", "rpcbindings", "invalid3"), "inconsistent usages of event `SomeEvent` against config: number of params mismatch: 2 vs 1")
 		})
 	*/
 	t.Run("extended types mismatch", func(t *testing.T) {
-		check(t, filepath.Join("testdata", "invalid8"), "inconsistent usages of event `SomeEvent`: extended type of param #0 mismatch")
+		check(t, filepath.Join("testdata", "rpcbindings", "invalid4"), "inconsistent usages of event `SomeEvent`: extended type of param #0 mismatch")
 	})
 	t.Run("named types redeclare", func(t *testing.T) {
-		check(t, filepath.Join("testdata", "invalid9"), "configured declared named type intersects with the contract's one: `invalid9.NamedStruct`")
+		check(t, filepath.Join("testdata", "rpcbindings", "invalid5"), "configured declared named type intersects with the contract's one: `invalid5.NamedStruct`")
+	})
+}
+
+func TestGenerateRPCBindings_Errors(t *testing.T) {
+	app := cli.NewApp()
+	app.Commands = NewCommands()
+	app.ExitErrHandler = func(*cli.Context, error) {}
+
+	t.Run("duplicating resulting fields", func(t *testing.T) {
+		check := func(t *testing.T, packageName string, autogen bool, expectedError string) {
+			tmpDir := t.TempDir()
+			source := filepath.Join("testdata", "rpcbindings", packageName)
+			configFile := filepath.Join(source, "invalid.yml")
+			out := filepath.Join(tmpDir, "rpcbindings.out")
+			manifestF := filepath.Join(tmpDir, "manifest.json")
+			bindingF := filepath.Join(tmpDir, "binding.yml")
+			nefF := filepath.Join(tmpDir, "out.nef")
+			cmd := []string{"", "contract", "compile",
+				"--in", source,
+				"--config", configFile,
+				"--manifest", manifestF,
+				"--bindings", bindingF,
+				"--out", nefF,
+			}
+			if autogen {
+				cmd = append(cmd, "--guess-eventtypes")
+			}
+			require.NoError(t, app.Run(cmd))
+
+			cmds := []string{"", "contract", "generate-rpcwrapper",
+				"--config", bindingF,
+				"--manifest", manifestF,
+				"--out", out,
+			}
+			err := app.Run(cmds)
+			require.Error(t, err)
+			require.True(t, strings.Contains(err.Error(), expectedError), err.Error())
+		}
+
+		t.Run("event", func(t *testing.T) {
+			check(t, "invalid6", false, "error during generation: named type `SomeStruct` has two fields with identical resulting binding name `Field`")
+		})
+		t.Run("autogen event", func(t *testing.T) {
+			check(t, "invalid7", true, "error during generation: named type `invalid7.SomeStruct` has two fields with identical resulting binding name `Field`")
+		})
+		t.Run("struct", func(t *testing.T) {
+			check(t, "invalid8", false, "error during generation: named type `invalid8.SomeStruct` has two fields with identical resulting binding name `Field`")
+		})
 	})
 }

cli/smartcontract/testdata/rpcbindings/invalid1/invalid.go

@@ -1,4 +1,4 @@
-package invalid5
+package invalid1
 
 import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 

cli/smartcontract/testdata/rpcbindings/invalid2/invalid.go

@@ -1,4 +1,4 @@
-package invalid6
+package invalid2
 
 import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 

cli/smartcontract/testdata/rpcbindings/invalid3/invalid.go

@@ -1,4 +1,4 @@
-package invalid7
+package invalid3
 
 import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 

cli/smartcontract/testdata/rpcbindings/invalid4/invalid.go

@@ -1,4 +1,4 @@
-package invalid8
+package invalid4
 
 import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 

cli/smartcontract/testdata/rpcbindings/invalid5/invalid.go

@@ -1,4 +1,4 @@
-package invalid9
+package invalid5
 
 import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 

cli/smartcontract/testdata/rpcbindings/invalid5/invalid.yml

@@ -6,11 +6,11 @@ events:
         type: Array
         extendedtype:
           base: Array
-          name: invalid9.NamedStruct
+          name: invalid5.NamedStruct
 namedtypes:
-  invalid9.NamedStruct:
+  invalid5.NamedStruct:
     base: Array
-    name: invalid9.NamedStruct
+    name: invalid5.NamedStruct
     fields:
       - field: SomeInt
         base: Integer

cli/smartcontract/testdata/rpcbindings/invalid6/invalid.go

@@ -0,0 +1,14 @@
+package invalid6
+
+import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
+
+type SomeStruct struct {
+	Field int
+	// RPC binding generator will convert this field into exported, which matches
+	// exactly the existing Field.
+	field int
+}
+
+func Main() {
+	runtime.Notify("SomeEvent", SomeStruct{Field: 123, field: 123})
+}

cli/smartcontract/testdata/rpcbindings/invalid6/invalid.yml

@@ -0,0 +1,18 @@
+name: Test duplicating event fields
+events:
+  - name: SomeEvent
+    parameters:
+      - name: p1
+        type: Struct
+        extendedtype:
+          base: Struct
+          name: SomeStruct
+namedtypes:
+  SomeStruct:
+    base: Struct
+    name: SomeStruct
+    fields:
+      - field: Field
+        base: Integer
+      - field: field
+        base: Integer

cli/smartcontract/testdata/rpcbindings/invalid7/invalid.go

@@ -0,0 +1,14 @@
+package invalid7
+
+import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
+
+type SomeStruct struct {
+	Field int
+	// RPC binding generator will convert this field into exported, which matches
+	// exactly the existing Field.
+	field int
+}
+
+func Main() {
+	runtime.Notify("SomeEvent", SomeStruct{Field: 123, field: 123})
+}

cli/smartcontract/testdata/rpcbindings/invalid7/invalid.yml

@@ -0,0 +1,6 @@
+name: Test duplicating autogenerated event fields
+events:
+  - name: SomeEvent
+    parameters:
+      - name: p1
+        type: Struct

cli/smartcontract/testdata/rpcbindings/invalid8/invalid.go

@@ -0,0 +1,16 @@
+package invalid8
+
+type SomeStruct struct {
+	Field int
+	// RPC binding generator will convert this field into exported, which matches
+	// exactly the existing Field.
+	field int
+}
+
+func Main() SomeStruct {
+	s := SomeStruct{
+		Field: 1,
+		field: 2,
+	}
+	return s
+}

cli/smartcontract/testdata/rpcbindings/invalid8/invalid.yml

@@ -0,0 +1 @@
+name: Test duplicating struct fields

cli/smartcontract/testdata/rpcbindings/notifications/config.yml

@@ -17,3 +17,7 @@ events:
     parameters:
       - name: a
         type: Array
+  - name: "SomeUnexportedField"
+    parameters:
+      - name: s
+        type: Struct

cli/smartcontract/testdata/rpcbindings/notifications/config_extended.yml

@@ -36,6 +36,13 @@ events:
             base: Array
             value:
               base: Integer
+  - name: "SomeUnexportedField"
+    parameters:
+      - name: s
+        type: Struct
+        extendedtype:
+          base: Struct
+          name: simpleStruct
 namedtypes:
   crazyStruct:
     base: Struct
@@ -45,3 +52,9 @@ namedtypes:
         base: Integer
       - field: B
         base: Boolean
+  simpleStruct:
+    base: Struct
+    name: simpleStruct
+    fields:
+      - field: i
+        base: Integer

cli/smartcontract/testdata/rpcbindings/notifications/config_guessed.yml

@@ -17,3 +17,7 @@ events:
     parameters:
       - name: a
         type: Array
+  - name: "SomeUnexportedField"
+    parameters:
+      - name: s
+        type: Struct

cli/smartcontract/testdata/rpcbindings/notifications/notifications.go

@@ -23,3 +23,11 @@ func Struct() {
 func Array() {
 	runtime.Notify("SomeArray", [][]int{})
 }
+
+// UnexportedField emits notification with unexported field that must be converted
+// to exported in the resulting RPC binding.
+func UnexportedField() {
+	runtime.Notify("SomeUnexportedField", struct {
+		i int
+	}{i: 123})
+}

cli/smartcontract/testdata/rpcbindings/notifications/rpcbindings.out

@@ -97,6 +97,11 @@ type SomeArrayEvent struct {
 	A []any
 }
 
+// SomeUnexportedFieldEvent represents "SomeUnexportedField" event emitted by the contract.
+type SomeUnexportedFieldEvent struct {
+	S []any
+}
+
 // Actor is used by Contract to call state-changing methods.
 type Actor interface {
 	MakeCall(contract util.Uint160, method string, params ...any) (*transaction.Transaction, error)
@@ -207,6 +212,28 @@ func (c *Contract) StructUnsigned() (*transaction.Transaction, error) {
 	return c.actor.MakeUnsignedCall(c.hash, "struct", nil)
 }
 
+// UnexportedField creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is signed and immediately sent to the network.
+// The values returned are its hash, ValidUntilBlock value and error if any.
+func (c *Contract) UnexportedField() (util.Uint256, uint32, error) {
+	return c.actor.SendCall(c.hash, "unexportedField")
+}
+
+// UnexportedFieldTransaction creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is signed, but not sent to the network, instead it's
+// returned to the caller.
+func (c *Contract) UnexportedFieldTransaction() (*transaction.Transaction, error) {
+	return c.actor.MakeCall(c.hash, "unexportedField")
+}
+
+// UnexportedFieldUnsigned creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is not signed, it's simply returned to the caller.
+// Any fields of it that do not affect fees can be changed (ValidUntilBlock,
+// Nonce), fee values (NetworkFee, SystemFee) can be increased as well.
+func (c *Contract) UnexportedFieldUnsigned() (*transaction.Transaction, error) {
+	return c.actor.MakeUnsignedCall(c.hash, "unexportedField", nil)
+}
+
 // itemToLedgerBlock converts stack item into *LedgerBlock.
 func itemToLedgerBlock(item stackitem.Item, err error) (*LedgerBlock, error) {
 	if err != nil {
@@ -1030,3 +1057,68 @@ func (e *SomeArrayEvent) FromStackItem(item *stackitem.Array) error {
 
 	return nil
 }
+
+// SomeUnexportedFieldEventsFromApplicationLog retrieves a set of all emitted events
+// with "SomeUnexportedField" name from the provided [result.ApplicationLog].
+func SomeUnexportedFieldEventsFromApplicationLog(log *result.ApplicationLog) ([]*SomeUnexportedFieldEvent, error) {
+	if log == nil {
+		return nil, errors.New("nil application log")
+	}
+
+	var res []*SomeUnexportedFieldEvent
+	for i, ex := range log.Executions {
+		for j, e := range ex.Events {
+			if e.Name != "SomeUnexportedField" {
+				continue
+			}
+			event := new(SomeUnexportedFieldEvent)
+			err := event.FromStackItem(e.Item)
+			if err != nil {
+				return nil, fmt.Errorf("failed to deserialize SomeUnexportedFieldEvent from stackitem (execution #%d, event #%d): %w", i, j, err)
+			}
+			res = append(res, event)
+		}
+	}
+
+	return res, nil
+}
+
+// FromStackItem converts provided [stackitem.Array] to SomeUnexportedFieldEvent or
+// returns an error if it's not possible to do to so.
+func (e *SomeUnexportedFieldEvent) FromStackItem(item *stackitem.Array) error {
+	if item == nil {
+		return errors.New("nil item")
+	}
+	arr, ok := item.Value().([]stackitem.Item)
+	if !ok {
+		return errors.New("not an array")
+	}
+	if len(arr) != 1 {
+		return errors.New("wrong number of structure elements")
+	}
+
+	var (
+		index = -1
+		err error
+	)
+	index++
+	e.S, err = func (item stackitem.Item) ([]any, error) {
+		arr, ok := item.Value().([]stackitem.Item)
+		if !ok {
+			return nil, errors.New("not an array")
+		}
+		res := make([]any, len(arr))
+		for i := range res {
+			res[i], err = arr[i].Value(), error(nil)
+			if err != nil {
+				return nil, fmt.Errorf("item %d: %w", i, err)
+			}
+		}
+		return res, nil
+	} (arr[index])
+	if err != nil {
+		return fmt.Errorf("field S: %w", err)
+	}
+
+	return nil
+}

cli/smartcontract/testdata/rpcbindings/notifications/rpcbindings_extended.out

@@ -83,6 +83,11 @@ type LedgerWitnessRule struct {
 	Condition *LedgerWitnessCondition
 }
 
+// SimpleStruct is a contract-specific simpleStruct type used by its methods.
+type SimpleStruct struct {
+	I *big.Int
+}
+
 // ComplicatedNameEvent represents "! complicated name %$#" event emitted by the contract.
 type ComplicatedNameEvent struct {
 	ComplicatedParam string
@@ -103,6 +108,11 @@ type SomeArrayEvent struct {
 	A [][]*big.Int
 }
 
+// SomeUnexportedFieldEvent represents "SomeUnexportedField" event emitted by the contract.
+type SomeUnexportedFieldEvent struct {
+	S *SimpleStruct
+}
+
 // Actor is used by Contract to call state-changing methods.
 type Actor interface {
 	MakeCall(contract util.Uint160, method string, params ...any) (*transaction.Transaction, error)
@@ -213,6 +223,28 @@ func (c *Contract) StructUnsigned() (*transaction.Transaction, error) {
 	return c.actor.MakeUnsignedCall(c.hash, "struct", nil)
 }
 
+// UnexportedField creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is signed and immediately sent to the network.
+// The values returned are its hash, ValidUntilBlock value and error if any.
+func (c *Contract) UnexportedField() (util.Uint256, uint32, error) {
+	return c.actor.SendCall(c.hash, "unexportedField")
+}
+
+// UnexportedFieldTransaction creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is signed, but not sent to the network, instead it's
+// returned to the caller.
+func (c *Contract) UnexportedFieldTransaction() (*transaction.Transaction, error) {
+	return c.actor.MakeCall(c.hash, "unexportedField")
+}
+
+// UnexportedFieldUnsigned creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is not signed, it's simply returned to the caller.
+// Any fields of it that do not affect fees can be changed (ValidUntilBlock,
+// Nonce), fee values (NetworkFee, SystemFee) can be increased as well.
+func (c *Contract) UnexportedFieldUnsigned() (*transaction.Transaction, error) {
+	return c.actor.MakeUnsignedCall(c.hash, "unexportedField", nil)
+}
+
 // itemToCrazyStruct converts stack item into *CrazyStruct.
 func itemToCrazyStruct(item stackitem.Item, err error) (*CrazyStruct, error) {
 	if err != nil {
@@ -816,6 +848,40 @@ func (res *LedgerWitnessRule) FromStackItem(item stackitem.Item) error {
 	return nil
 }
 
+// itemToSimpleStruct converts stack item into *SimpleStruct.
+func itemToSimpleStruct(item stackitem.Item, err error) (*SimpleStruct, error) {
+	if err != nil {
+		return nil, err
+	}
+	var res = new(SimpleStruct)
+	err = res.FromStackItem(item)
+	return res, err
+}
+
+// FromStackItem retrieves fields of SimpleStruct from the given
+// [stackitem.Item] or returns an error if it's not possible to do to so.
+func (res *SimpleStruct) FromStackItem(item stackitem.Item) error {
+	arr, ok := item.Value().([]stackitem.Item)
+	if !ok {
+		return errors.New("not an array")
+	}
+	if len(arr) != 1 {
+		return errors.New("wrong number of structure elements")
+	}
+
+	var (
+		index = -1
+		err error
+	)
+	index++
+	res.I, err = arr[index].TryInteger()
+	if err != nil {
+		return fmt.Errorf("field I: %w", err)
+	}
+
+	return nil
+}
+
 // ComplicatedNameEventsFromApplicationLog retrieves a set of all emitted events
 // with "! complicated name %$#" name from the provided [result.ApplicationLog].
 func ComplicatedNameEventsFromApplicationLog(log *result.ApplicationLog) ([]*ComplicatedNameEvent, error) {
@@ -1126,3 +1192,55 @@ func (e *SomeArrayEvent) FromStackItem(item *stackitem.Array) error {
 
 	return nil
 }
+
+// SomeUnexportedFieldEventsFromApplicationLog retrieves a set of all emitted events
+// with "SomeUnexportedField" name from the provided [result.ApplicationLog].
+func SomeUnexportedFieldEventsFromApplicationLog(log *result.ApplicationLog) ([]*SomeUnexportedFieldEvent, error) {
+	if log == nil {
+		return nil, errors.New("nil application log")
+	}
+
+	var res []*SomeUnexportedFieldEvent
+	for i, ex := range log.Executions {
+		for j, e := range ex.Events {
+			if e.Name != "SomeUnexportedField" {
+				continue
+			}
+			event := new(SomeUnexportedFieldEvent)
+			err := event.FromStackItem(e.Item)
+			if err != nil {
+				return nil, fmt.Errorf("failed to deserialize SomeUnexportedFieldEvent from stackitem (execution #%d, event #%d): %w", i, j, err)
+			}
+			res = append(res, event)
+		}
+	}
+
+	return res, nil
+}
+
+// FromStackItem converts provided [stackitem.Array] to SomeUnexportedFieldEvent or
+// returns an error if it's not possible to do to so.
+func (e *SomeUnexportedFieldEvent) FromStackItem(item *stackitem.Array) error {
+	if item == nil {
+		return errors.New("nil item")
+	}
+	arr, ok := item.Value().([]stackitem.Item)
+	if !ok {
+		return errors.New("not an array")
+	}
+	if len(arr) != 1 {
+		return errors.New("wrong number of structure elements")
+	}
+
+	var (
+		index = -1
+		err error
+	)
+	index++
+	e.S, err = itemToSimpleStruct(arr[index], nil)
+	if err != nil {
+		return fmt.Errorf("field S: %w", err)
+	}
+
+	return nil
+}

cli/smartcontract/testdata/rpcbindings/notifications/rpcbindings_guessed.out

@@ -103,6 +103,11 @@ type SomeArrayEvent struct {
 	A [][]*big.Int
 }
 
+// SomeUnexportedFieldEvent represents "SomeUnexportedField" event emitted by the contract.
+type SomeUnexportedFieldEvent struct {
+	S *Unnamed
+}
+
 // Actor is used by Contract to call state-changing methods.
 type Actor interface {
 	MakeCall(contract util.Uint160, method string, params ...any) (*transaction.Transaction, error)
@@ -213,6 +218,28 @@ func (c *Contract) StructUnsigned() (*transaction.Transaction, error) {
 	return c.actor.MakeUnsignedCall(c.hash, "struct", nil)
 }
 
+// UnexportedField creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is signed and immediately sent to the network.
+// The values returned are its hash, ValidUntilBlock value and error if any.
+func (c *Contract) UnexportedField() (util.Uint256, uint32, error) {
+	return c.actor.SendCall(c.hash, "unexportedField")
+}
+
+// UnexportedFieldTransaction creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is signed, but not sent to the network, instead it's
+// returned to the caller.
+func (c *Contract) UnexportedFieldTransaction() (*transaction.Transaction, error) {
+	return c.actor.MakeCall(c.hash, "unexportedField")
+}
+
+// UnexportedFieldUnsigned creates a transaction invoking `unexportedField` method of the contract.
+// This transaction is not signed, it's simply returned to the caller.
+// Any fields of it that do not affect fees can be changed (ValidUntilBlock,
+// Nonce), fee values (NetworkFee, SystemFee) can be increased as well.
+func (c *Contract) UnexportedFieldUnsigned() (*transaction.Transaction, error) {
+	return c.actor.MakeUnsignedCall(c.hash, "unexportedField", nil)
+}
+
 // itemToLedgerBlock converts stack item into *LedgerBlock.
 func itemToLedgerBlock(item stackitem.Item, err error) (*LedgerBlock, error) {
 	if err != nil {
@@ -1139,3 +1166,55 @@ func (e *SomeArrayEvent) FromStackItem(item *stackitem.Array) error {
 
 	return nil
 }
+
+// SomeUnexportedFieldEventsFromApplicationLog retrieves a set of all emitted events
+// with "SomeUnexportedField" name from the provided [result.ApplicationLog].
+func SomeUnexportedFieldEventsFromApplicationLog(log *result.ApplicationLog) ([]*SomeUnexportedFieldEvent, error) {
+	if log == nil {
+		return nil, errors.New("nil application log")
+	}
+
+	var res []*SomeUnexportedFieldEvent
+	for i, ex := range log.Executions {
+		for j, e := range ex.Events {
+			if e.Name != "SomeUnexportedField" {
+				continue
+			}
+			event := new(SomeUnexportedFieldEvent)
+			err := event.FromStackItem(e.Item)
+			if err != nil {
+				return nil, fmt.Errorf("failed to deserialize SomeUnexportedFieldEvent from stackitem (execution #%d, event #%d): %w", i, j, err)
+			}
+			res = append(res, event)
+		}
+	}
+
+	return res, nil
+}
+
+// FromStackItem converts provided [stackitem.Array] to SomeUnexportedFieldEvent or
+// returns an error if it's not possible to do to so.
+func (e *SomeUnexportedFieldEvent) FromStackItem(item *stackitem.Array) error {
+	if item == nil {
+		return errors.New("nil item")
+	}
+	arr, ok := item.Value().([]stackitem.Item)
+	if !ok {
+		return errors.New("not an array")
+	}
+	if len(arr) != 1 {
+		return errors.New("wrong number of structure elements")
+	}
+
+	var (
+		index = -1
+		err error
+	)
+	index++
+	e.S, err = itemToUnnamed(arr[index], nil)
+	if err != nil {
+		return fmt.Errorf("field S: %w", err)
+	}
+
+	return nil
+}

cli/smartcontract/testdata/rpcbindings/structs/rpcbindings.out

@@ -152,6 +152,7 @@ type StructsInternal struct {
 	ArrOfH160 []util.Uint160
 	Map map[*big.Int]keys.PublicKeys
 	Struct *StructsInternal
+	UnexportedField *big.Int
 }
 
 // Invoker is used by ContractReader to call various safe methods.
@@ -1410,7 +1411,7 @@ func (res *StructsInternal) FromStackItem(item stackitem.Item) error {
 	if !ok {
 		return errors.New("not an array")
 	}
-	if len(arr) != 13 {
+	if len(arr) != 14 {
 		return errors.New("wrong number of structure elements")
 	}
 
@@ -1622,5 +1623,11 @@ func (res *StructsInternal) FromStackItem(item stackitem.Item) error {
 		return fmt.Errorf("field Struct: %w", err)
 	}
 
+	index++
+	res.UnexportedField, err = arr[index].TryInteger()
+	if err != nil {
+		return fmt.Errorf("field UnexportedField: %w", err)
+	}
+
 	return nil
 }

cli/smartcontract/testdata/rpcbindings/structs/rpcbindings_dynamic_hash.out

@@ -149,6 +149,7 @@ type StructsInternal struct {
 	ArrOfH160 []util.Uint160
 	Map map[*big.Int]keys.PublicKeys
 	Struct *StructsInternal
+	UnexportedField *big.Int
 }
 
 // Invoker is used by ContractReader to call various safe methods.
@@ -1406,7 +1407,7 @@ func (res *StructsInternal) FromStackItem(item stackitem.Item) error {
 	if !ok {
 		return errors.New("not an array")
 	}
-	if len(arr) != 13 {
+	if len(arr) != 14 {
 		return errors.New("wrong number of structure elements")
 	}
 
@@ -1618,5 +1619,11 @@ func (res *StructsInternal) FromStackItem(item stackitem.Item) error {
 		return fmt.Errorf("field Struct: %w", err)
 	}
 
+	index++
+	res.UnexportedField, err = arr[index].TryInteger()
+	if err != nil {
+		return fmt.Errorf("field UnexportedField: %w", err)
+	}
+
 	return nil
 }

cli/smartcontract/testdata/rpcbindings/structs/structs.go

@@ -0,0 +1,40 @@
+package structs
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop"
+	"github.com/nspcc-dev/neo-go/pkg/interop/native/ledger"
+	"github.com/nspcc-dev/neo-go/pkg/interop/native/management"
+)
+
+type Internal struct {
+	Bool            bool
+	Int             int
+	Bytes           []byte
+	String          string
+	H160            interop.Hash160
+	H256            interop.Hash256
+	PK              interop.PublicKey
+	PubKey          interop.PublicKey
+	Sign            interop.Signature
+	ArrOfBytes      [][]byte
+	ArrOfH160       []interop.Hash160
+	Map             map[int][]interop.PublicKey
+	Struct          *Internal
+	unexportedField int // this one should be exported in the resulting RPC binding.
+}
+
+func Contract(mc management.Contract) management.Contract {
+	return mc
+}
+
+func Block(b *ledger.Block) *ledger.Block {
+	return b
+}
+
+func Transaction(t *ledger.Transaction) *ledger.Transaction {
+	return t
+}
+
+func Struct(s *Internal) *Internal {
+	return s
+}

cli/smartcontract/testdata/structs/structs.go

@@ -1,39 +0,0 @@
-package structs
-
-import (
-	"github.com/nspcc-dev/neo-go/pkg/interop"
-	"github.com/nspcc-dev/neo-go/pkg/interop/native/ledger"
-	"github.com/nspcc-dev/neo-go/pkg/interop/native/management"
-)
-
-type Internal struct {
-	Bool       bool
-	Int        int
-	Bytes      []byte
-	String     string
-	H160       interop.Hash160
-	H256       interop.Hash256
-	PK         interop.PublicKey
-	PubKey     interop.PublicKey
-	Sign       interop.Signature
-	ArrOfBytes [][]byte
-	ArrOfH160  []interop.Hash160
-	Map        map[int][]interop.PublicKey
-	Struct     *Internal
-}
-
-func Contract(mc management.Contract) management.Contract {
-	return mc
-}
-
-func Block(b *ledger.Block) *ledger.Block {
-	return b
-}
-
-func Transaction(t *ledger.Transaction) *ledger.Transaction {
-	return t
-}
-
-func Struct(s *Internal) *Internal {
-	return s
-}

pkg/smartcontract/rpcbinding/binding.go

@@ -23,7 +23,7 @@ const (
 // {{.Name}} represents "{{.ManifestName}}" event emitted by the contract.
 type {{.Name}} struct {
 	{{- range $index, $arg := .Parameters}}
-	{{.Name}} {{.Type}}
+	{{ upperFirst .Name}} {{.Type}}
 	{{- end}}
 }
 {{ end }}`
@@ -126,7 +126,7 @@ var Hash = {{ .Hash }}
 // {{toTypeName $name}} is a contract-specific {{$name}} type used by its methods.
 type {{toTypeName $name}} struct {
 {{- range $m := $typ.Fields}}
-	{{.Field}} {{etTypeToStr .ExtendedType}}
+	{{ upperFirst .Field}} {{etTypeToStr .ExtendedType}}
 {{- end}}
 }
 {{end}}
@@ -262,9 +262,9 @@ func (res *{{toTypeName $name}}) FromStackItem(item stackitem.Item) error {
 	)
 {{- range $m := $typ.Fields}}
 	index++
-	res.{{.Field}}, err = {{etTypeConverter .ExtendedType "arr[index]"}}
+	res.{{ upperFirst .Field}}, err = {{etTypeConverter .ExtendedType "arr[index]"}}
 	if err != nil {
-		return fmt.Errorf("field {{.Field}}: %w", err)
+		return fmt.Errorf("field {{ upperFirst .Field}}: %w", err)
 	}
 {{end}}
 {{- end}}
@@ -317,9 +317,9 @@ func (e *{{$e.Name}}) FromStackItem(item *stackitem.Array) error {
 	)
 	{{- range $p := $e.Parameters}}
 	index++
-	e.{{.Name}}, err = {{etTypeConverter .ExtType "arr[index]"}}
+	e.{{ upperFirst .Name}}, err = {{etTypeConverter .ExtType "arr[index]"}}
 	if err != nil {
-		return fmt.Errorf("field {{.Name}}: %w", err)
+		return fmt.Errorf("field {{ upperFirst .Name}}: %w", err)
 	}
 {{end}}
 {{- end}}
@@ -430,6 +430,28 @@ func Generate(cfg binding.Config) error {
 	ctr = scTemplateToRPC(cfg, ctr, imports, scTypeToGo)
 	ctr.NamedTypes = cfg.NamedTypes
 
+	// Check resulting named types and events don't have duplicating field names.
+	for _, t := range ctr.NamedTypes {
+		fDict := make(map[string]struct{})
+		for _, n := range t.Fields {
+			name := upperFirst(n.Field)
+			if _, ok := fDict[name]; ok {
+				return fmt.Errorf("named type `%s` has two fields with identical resulting binding name `%s`", t.Name, name)
+			}
+			fDict[name] = struct{}{}
+		}
+	}
+	for _, e := range ctr.CustomEvents {
+		fDict := make(map[string]struct{})
+		for _, n := range e.Parameters {
+			name := upperFirst(n.Name)
+			if _, ok := fDict[name]; ok {
+				return fmt.Errorf("event `%s` has two fields with identical resulting binding name `%s`", e.Name, name)
+			}
+			fDict[name] = struct{}{}
+		}
+	}
+
 	var srcTemplate = template.Must(template.New("generate").Funcs(template.FuncMap{
 		"addIndent":       addIndent,
 		"etTypeConverter": etTypeConverter,
@@ -439,6 +461,7 @@ func Generate(cfg binding.Config) error {
 		},
 		"toTypeName": toTypeName,
 		"cutPointer": cutPointer,
+		"upperFirst": upperFirst,
 	}).Parse(srcTmpl))
 
 	return srcTemplate.Execute(cfg.Output, ctr)
@@ -863,7 +886,7 @@ func toTypeName(s string) string {
 			return -1
 		}
 		return c
-	}, strings.ToUpper(s[0:1])+s[1:])
+	}, upperFirst(s))
 }
 
 func addIndent(str string, ind string) string {