add generic log watching/filtering. skip adding generic call/transact (issue with interface regarding contract methods that don't take arguments)

accounts/abi/bind/base.go

@@ -460,9 +460,9 @@ func (c *BoundContract) transact(opts *TransactOpts, contract *common.Address, i
 	return signedTx, nil
 }
 
-// FilterLogsByID filters contract logs for past blocks, returning the necessary
+// FilterLogsById filters contract logs for past blocks, returning the necessary
 // channels to construct a strongly typed bound iterator on top of them.
-func (c *BoundContract) FilterLogsByID(opts *FilterOpts, eventID common.Hash, query ...[]interface{}) (<-chan types.Log, event.Subscription, error) {
+func (c *BoundContract) FilterLogsById(opts *FilterOpts, eventID common.Hash, query ...[]interface{}) (<-chan types.Log, event.Subscription, error) {
 	return c.filterLogs(opts, eventID, query...)
 }
 

accounts/abi/bind/source2.go.tpl

@@ -125,7 +125,9 @@ var (
 		}
 
 		func (_{{$contract.Type}} *{{$contract.Type}}) Unpack{{.Normalized.Name}}Event(log *types.Log) (*{{$contract.Type}}{{.Normalized.Name}}, error) {
-			event := "{{.Normalized.Name}}"
+		    // TODO: okay to index by the original name here?  I think so because we assume that the abi json is well-formed.
+		    // and we only need normalized name when dealing with generated go symbols.
+			event := "{{.Original.Name}}"
 			if log.Topics[0] != _{{$contract.Type}}.abi.Events[event].ID {
 				return nil, errors.New("event signature mismatch")
 			}

accounts/abi/bind/testdata/v2/events/bindings.go

@@ -134,7 +134,9 @@ func CBasic1EventID() common.Hash {
 }
 
 func (_C *C) UnpackBasic1Event(log *types.Log) (*CBasic1, error) {
-	event := "Basic1"
+	// TODO: okay to index by the original name here?  I think so because we assume that the abi json is well-formed.
+	// and we only need normalized name when dealing with generated go symbols.
+	event := "basic1"
 	if log.Topics[0] != _C.abi.Events[event].ID {
 		return nil, errors.New("event signature mismatch")
 	}
@@ -169,7 +171,9 @@ func CBasic2EventID() common.Hash {
 }
 
 func (_C *C) UnpackBasic2Event(log *types.Log) (*CBasic2, error) {
-	event := "Basic2"
+	// TODO: okay to index by the original name here?  I think so because we assume that the abi json is well-formed.
+	// and we only need normalized name when dealing with generated go symbols.
+	event := "basic2"
 	if log.Topics[0] != _C.abi.Events[event].ID {
 		return nil, errors.New("event signature mismatch")
 	}

accounts/abi/bind/v2/lib.go

@@ -19,9 +19,12 @@ package v2
 import (
 	"encoding/hex"
 	"fmt"
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts/abi"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/event"
 	"regexp"
 	"strings"
 )
@@ -212,3 +215,149 @@ func LinkAndDeploy(auth *bind.TransactOpts, backend bind.ContractBackend, deploy
 
 	return res, nil
 }
+
+// TODO: this will be generated as part of the bindings, contain the ABI (or metadata object?) and errors
+type ContractInstance struct {
+	Address common.Address
+	Backend bind.ContractBackend
+}
+
+// TODO: adding docs soon (jwasinger)
+func FilterEvents[T any](instance *ContractInstance, opts *bind.FilterOpts, eventID common.Hash, unpack func(*types.Log) (*T, error), topics ...[]any) (*EventIterator[T], error) {
+	backend := instance.Backend
+	c := bind.NewBoundContract(instance.Address, abi.ABI{}, backend, backend, backend)
+	logs, sub, err := c.FilterLogsById(opts, eventID, topics...)
+	if err != nil {
+		return nil, err
+	}
+	return &EventIterator[T]{unpack: unpack, logs: logs, sub: sub}, nil
+}
+
+// WatchEvents causes logs emitted with a given event id from a specified
+// contract to be intercepted, unpacked, and forwarded to sink.  If
+// unpack returns an error, the returned subscription is closed with the
+// error.
+func WatchEvents[T any](instance *ContractInstance, abi abi.ABI, opts *bind.WatchOpts, eventID common.Hash, unpack func(*types.Log) (*T, error), sink chan<- *T, topics ...[]any) (event.Subscription, error) {
+	backend := instance.Backend
+	c := bind.NewBoundContract(instance.Address, abi, backend, backend, backend)
+	logs, sub, err := c.WatchLogsForId(opts, eventID, topics...)
+	if err != nil {
+		return nil, err
+	}
+	return event.NewSubscription(func(quit <-chan struct{}) error {
+		defer sub.Unsubscribe()
+		for {
+			select {
+			case log := <-logs:
+				// New log arrived, parse the event and forward to the user
+				ev, err := unpack(&log)
+				if err != nil {
+					fmt.Printf("unpack err: %v", err)
+					return err
+				}
+
+				select {
+				case sink <- ev:
+				case err := <-sub.Err():
+					return err
+				case <-quit:
+					return nil
+				}
+			case err := <-sub.Err():
+				return err
+			case <-quit:
+				return nil
+			}
+		}
+	}), nil
+}
+
+// EventIterator is returned from FilterLogs and is used to iterate over the raw logs and unpacked data for events.
+type EventIterator[T any] struct {
+	event *T // event containing the contract specifics and raw log
+
+	unpack func(*types.Log) (*T, error) // Unpack function for the event
+
+	logs <-chan types.Log      // Log channel receiving the found contract events
+	sub  ethereum.Subscription // Subscription for solc_errors, completion and termination
+	done bool                  // Whether the subscription completed delivering logs
+	fail error                 // Occurred error to stop iteration
+}
+
+// Value returns the current value of the iterator, or nil if there isn't one.
+func (it *EventIterator[T]) Value() *T {
+	return it.event
+}
+
+// Next advances the iterator to the subsequent event, returning whether there
+// are any more events found. In case of a retrieval or parsing error, false is
+// returned and Error() can be queried for the exact failure.
+func (it *EventIterator[T]) Next() bool {
+	// If the iterator failed, stop iterating
+	if it.fail != nil {
+		return false
+	}
+	// If the iterator completed, deliver directly whatever's available
+	if it.done {
+		select {
+		case log := <-it.logs:
+			res, err := it.unpack(&log)
+			if err != nil {
+				it.fail = err
+				return false
+			}
+			it.event = res
+			return true
+
+		default:
+			return false
+		}
+	}
+	// Iterator still in progress, wait for either a data or an error event
+	select {
+	case log := <-it.logs:
+		res, err := it.unpack(&log)
+		if err != nil {
+			it.fail = err
+			return false
+		}
+		it.event = res
+		return true
+
+	case err := <-it.sub.Err():
+		it.done = true
+		it.fail = err
+		return it.Next()
+	}
+}
+
+// Error returns any retrieval or parsing error occurred during filtering.
+func (it *EventIterator[T]) Error() error {
+	return it.fail
+}
+
+// Close terminates the iteration process, releasing any pending underlying
+// resources.
+func (it *EventIterator[T]) Close() error {
+	it.sub.Unsubscribe()
+	return nil
+}
+
+// Transact creates and submits a transaction to the bound contract instance
+// using the provided abi-encoded input (or nil).
+func Transact(instance *ContractInstance, opts *bind.TransactOpts, packedInput []byte) (*types.Transaction, error) {
+	var (
+		addr    = instance.Address
+		backend = instance.Backend
+	)
+	c := bind.NewBoundContract(addr, abi.ABI{}, backend, backend, backend)
+	return c.RawTransact(opts, packedInput)
+}
+
+// Call performs an eth_call on the given bound contract instance, using the
+// provided abi-encoded input (or nil).
+func Call(instance *ContractInstance, opts *bind.CallOpts, packedInput []byte) ([]byte, error) {
+	backend := instance.Backend
+	c := bind.NewBoundContract(instance.Address, abi.ABI{}, backend, backend, backend)
+	return c.CallRaw(opts, packedInput)
+}

accounts/abi/bind/v2/lib_test.go

@@ -269,7 +269,6 @@ func TestDeploymentWithOverrides(t *testing.T) {
 		t.Fatalf("expected internal call count of 6.  got %d.", internalCallCount.Uint64())
 	}
 }
-
 func TestEvents(t *testing.T) {
 	// test watch/filter logs method on a contract that emits various kinds of events (struct-containing, etc.)
 	txAuth, backend, err := testSetup()
@@ -305,31 +304,30 @@ func TestEvents(t *testing.T) {
 		t.Fatalf("error getting contract abi: %v", err)
 	}
 
-	boundContract := bind.NewBoundContract(res.Addrs[events.CMetaData.Pattern], *abi, backend, backend, backend)
+	boundContract := ContractInstance{
+		res.Addrs[events.CMetaData.Pattern],
+		backend,
+	}
 
+	newCBasic1Ch := make(chan *events.CBasic1)
+	newCBasic2Ch := make(chan *events.CBasic2)
 	watchOpts := &bind.WatchOpts{
 		Start:   nil,
 		Context: context.Background(),
 	}
-	chE1, sub1, err := boundContract.WatchLogsForId(watchOpts, events.CBasic1EventID(), nil)
-	if err != nil {
-		t.Fatalf("WatchLogsForId with event type 1 failed: %v", err)
-	}
+	sub1, err := WatchEvents(&boundContract, *abi, watchOpts, events.CBasic1EventID(), ctrct.UnpackBasic1Event, newCBasic1Ch)
+	sub2, err := WatchEvents(&boundContract, *abi, watchOpts, events.CBasic2EventID(), ctrct.UnpackBasic2Event, newCBasic2Ch)
 	defer sub1.Unsubscribe()
-
-	chE2, sub2, err := boundContract.WatchLogsForId(watchOpts, events.CBasic2EventID(), nil)
-	if err != nil {
-		t.Fatalf("WatchLogsForId with event type 2 failed: %v", err)
-	}
 	defer sub2.Unsubscribe()
 
-	packedCallData, err := ctrct.PackEmitMulti()
-	if err != nil {
-		t.Fatalf("failed to pack EmitMulti arguments")
+	crtctInstance := &ContractInstance{
+		Address: res.Addrs[events.CMetaData.Pattern],
+		Backend: backend,
 	}
-	tx, err := boundContract.RawTransact(txAuth, packedCallData)
+	packedInput, _ := ctrct.PackEmitMulti()
+	tx, err := Transact(crtctInstance, txAuth, packedInput)
 	if err != nil {
-		t.Fatalf("failed to submit transaction: %v", err)
+		t.Fatalf("failed to send transaction: %v", err)
 	}
 	backend.Commit()
 	if _, err := bind.WaitMined(context.Background(), backend, tx); err != nil {
@@ -341,22 +339,15 @@ func TestEvents(t *testing.T) {
 	e2Count := 0
 	for {
 		select {
-		case <-timeout.C:
-			goto done
-		case err := <-sub1.Err():
-			t.Fatalf("received err from sub1: %v", err)
-		case err := <-sub2.Err():
-			t.Fatalf("received err from sub2: %v", err)
-		case log := <-chE1:
-			if _, err := ctrct.UnpackBasic1Event(&log); err != nil {
-				t.Fatalf("failed to unpack basic1 type event: %v", err)
-			}
+		case _ = <-newCBasic1Ch:
 			e1Count++
-		case log := <-chE2:
-			if _, err := ctrct.UnpackBasic2Event(&log); err != nil {
-				t.Fatalf("failed to unpack basic2 type event: %v", err)
-			}
+		case _ = <-newCBasic2Ch:
 			e2Count++
+		case _ = <-timeout.C:
+			goto done
+		}
+		if e1Count == 2 && e2Count == 1 {
+			break
 		}
 	}
 done:
@@ -373,33 +364,39 @@ done:
 		Start:   0,
 		Context: context.Background(),
 	}
-	chE1, sub1, err = boundContract.FilterLogsByID(filterOpts, events.CBasic1EventID(), nil)
-	if err != nil {
-		t.Fatalf("failed to filter logs for event type 1: %v", err)
+	unpackBasic := func(raw *types.Log) (*events.CBasic1, error) {
+		return &events.CBasic1{
+			Id:   (new(big.Int)).SetBytes(raw.Topics[0].Bytes()),
+			Data: (new(big.Int)).SetBytes(raw.Data),
+		}, nil
 	}
-	chE2, sub2, err = boundContract.FilterLogsByID(filterOpts, events.CBasic2EventID(), nil)
-	if err != nil {
-		t.Fatalf("failed to filter logs for event type 2: %v", err)
+	unpackBasic2 := func(raw *types.Log) (*events.CBasic2, error) {
+		return &events.CBasic2{
+			Flag: false, // TODO: how to unpack different types to go types?  this should be exposed via abi package.
+			Data: (new(big.Int)).SetBytes(raw.Data),
+		}, nil
+	}
+	it, err := FilterEvents[events.CBasic1](crtctInstance, filterOpts, events.CBasic1EventID(), unpackBasic)
+	if err != nil {
+		t.Fatalf("error filtering logs %v\n", err)
+	}
+	it2, err := FilterEvents[events.CBasic2](crtctInstance, filterOpts, events.CBasic2EventID(), unpackBasic2)
+	if err != nil {
+		t.Fatalf("error filtering logs %v\n", err)
 	}
-	timeout.Reset(2 * time.Second)
 	e1Count = 0
 	e2Count = 0
-	for {
-		select {
-		case <-timeout.C:
-			goto done2
-		case <-chE1:
-			e1Count++
-		case <-chE2:
-			e2Count++
-		}
+	for it.Next() {
+		e1Count++
+	}
+	for it2.Next() {
+		e2Count++
 	}
-done2:
 	if e1Count != 2 {
-		t.Fatalf("incorrect results from filter logs: expected event type 1 count to be 2.  got %d", e1Count)
+		t.Fatalf("expected e1Count of 2 from filter call.  got %d", e1Count)
 	}
 	if e2Count != 1 {
-		t.Fatalf("incorrect results from filter logs: expected event type 2 count to be 1.  got %d", e2Count)
+		t.Fatalf("expected e2Count of 1 from filter call.  got %d", e1Count)
 	}
 }
 
@@ -409,7 +406,6 @@ func TestBindingGeneration(t *testing.T) {
 	for _, match := range matches {
 		f, _ := os.Stat(match)
 		if f.IsDir() {
-			fmt.Printf("match %s\n", f.Name())
 			dirs = append(dirs, f.Name())
 		}
 	}
@@ -433,8 +429,6 @@ func TestBindingGeneration(t *testing.T) {
 			t.Fatalf("Failed to read contract information from json output: %v", err)
 		}
 
-		fmt.Println(dir)
-		fmt.Printf("number of contracts: %d\n", len(contracts))
 		for name, contract := range contracts {
 			// fully qualified name is of the form <solFilePath>:<type>
 			nameParts := strings.Split(name, ":")