Shift replayer to prefer io.Reader rather than filenames (#1234)

This allows us to move to `//go:embed` or use hard-coded strings (or any other data-source).
Short-term plans are to use go:embed to read files once / not require runtime access to files, only build.

internal/workflow_replayer.go

@@ -26,6 +26,10 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
+	"math"
+	"os"
+
 	"github.com/golang/mock/gomock"
 	"github.com/opentracing/opentracing-go"
 	"github.com/pborman/uuid"
@@ -37,8 +41,6 @@ import (
 	"go.uber.org/cadence/internal/common/backoff"
 	"go.uber.org/cadence/internal/common/serializer"
 	"go.uber.org/zap"
-	"io/ioutil"
-	"math"
 )
 
 const (
@@ -133,19 +135,12 @@ func (r *WorkflowReplayer) ReplayWorkflowHistory(logger *zap.Logger, history *sh
 	return r.replayWorkflowHistory(logger, service, replayDomainName, nil, history, nil)
 }
 
-// ReplayWorkflowHistoryFromJSONFile executes a single decision task for the given json history file.
-// Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
-// The logger is an optional parameter. Defaults to the noop logger.
-func (r *WorkflowReplayer) ReplayWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string) error {
-	return r.ReplayPartialWorkflowHistoryFromJSONFile(logger, jsonfileName, 0)
+func (r *WorkflowReplayer) ReplayWorkflowHistoryFromJSON(logger *zap.Logger, reader io.Reader) error {
+	return r.ReplayPartialWorkflowHistoryFromJSON(logger, reader, 0)
 }
 
-// ReplayPartialWorkflowHistoryFromJSONFile executes a single decision task for the given json history file up to provided
-// lastEventID(inclusive).
-// Use for testing backwards compatibility of code changes and troubleshooting workflows in a debugger.
-// The logger is an optional parameter. Defaults to the noop logger.
-func (r *WorkflowReplayer) ReplayPartialWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string, lastEventID int64) error {
-	history, err := extractHistoryFromFile(jsonfileName, lastEventID)
+func (r *WorkflowReplayer) ReplayPartialWorkflowHistoryFromJSON(logger *zap.Logger, reader io.Reader, lastEventID int64) error {
+	history, err := extractHistoryFromReader(reader, lastEventID)
 
 	if err != nil {
 		return err
@@ -162,6 +157,28 @@ func (r *WorkflowReplayer) ReplayPartialWorkflowHistoryFromJSONFile(logger *zap.
 	return r.replayWorkflowHistory(logger, service, replayDomainName, nil, history, nil)
 }
 
+// ReplayWorkflowHistoryFromJSONFile executes a single decision task for the given json history file.
+// Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
+// The logger is an optional parameter. Defaults to the noop logger.
+func (r *WorkflowReplayer) ReplayWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string) error {
+	return r.ReplayPartialWorkflowHistoryFromJSONFile(logger, jsonfileName, 0)
+}
+
+// ReplayPartialWorkflowHistoryFromJSONFile executes a single decision task for the given json history file up to provided
+// lastEventID(inclusive).
+// Use for testing backwards compatibility of code changes and troubleshooting workflows in a debugger.
+// The logger is an optional parameter. Defaults to the noop logger.
+func (r *WorkflowReplayer) ReplayPartialWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string, lastEventID int64) error {
+	file, err := os.Open(jsonfileName)
+	if err != nil {
+		return fmt.Errorf("could not open file: %w", err)
+	}
+	defer func() {
+		_ = file.Close()
+	}()
+	return r.ReplayPartialWorkflowHistoryFromJSON(logger, file, lastEventID)
+}
+
 // ReplayWorkflowExecution replays workflow execution loading it from Cadence service.
 // The logger is an optional parameter. Defaults to the noop logger.
 func (r *WorkflowReplayer) ReplayWorkflowExecution(
@@ -336,17 +353,17 @@ func (r *WorkflowReplayer) replayWorkflowHistory(
 	return fmt.Errorf("replay workflow doesn't return the same result as the last event, resp: %v, last: %v", resp, last)
 }
 
-func extractHistoryFromFile(jsonfileName string, lastEventID int64) (*shared.History, error) {
-	raw, err := ioutil.ReadFile(jsonfileName)
+func extractHistoryFromReader(r io.Reader, lastEventID int64) (*shared.History, error) {
+	raw, err := io.ReadAll(r)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to read data: %w", err)
 	}
 
 	var deserializedEvents []*shared.HistoryEvent
 	err = json.Unmarshal(raw, &deserializedEvents)
 
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("invalid json contents: %w", err)
 	}
 
 	if lastEventID <= 0 {

worker/worker.go

@@ -24,6 +24,7 @@ package worker
 
 import (
 	"context"
+	"io"
 
 	"go.uber.org/cadence/.gen/go/cadence/workflowserviceclient"
 	"go.uber.org/cadence/.gen/go/shared"
@@ -151,6 +152,8 @@ type (
 		// See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation
 		// Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
 		// The logger is an optional parameter. Defaults to the noop logger.
+		//
+		// Deprecated: prefer ReplayWorkflowHistoryFromJSON
 		ReplayWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string) error
 
 		// ReplayPartialWorkflowHistoryFromJSONFile executes a single decision task for the json history file upto provided
@@ -159,12 +162,31 @@ type (
 		// See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation
 		// Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
 		// The logger is an optional parameter. Defaults to the noop logger.
+		//
+		// Deprecated: prefer ReplayPartialWorkflowHistoryFromJSON
 		ReplayPartialWorkflowHistoryFromJSONFile(logger *zap.Logger, jsonfileName string, lastEventID int64) error
 
 		// ReplayWorkflowExecution loads a workflow execution history from the Cadence service and executes a single decision task for it.
 		// Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
 		// The logger is the only optional parameter. Defaults to the noop logger.
 		ReplayWorkflowExecution(ctx context.Context, service workflowserviceclient.Interface, logger *zap.Logger, domain string, execution workflow.Execution) error
+
+		// ReplayWorkflowHistoryFromJSON executes a single decision task for the json history file downloaded from the cli.
+		// To download the history file:
+		//  cadence workflow showid <workflow_id> -of <output_filename>
+		// See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation
+		// Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
+		// The logger is an optional parameter. Defaults to the noop logger.
+		ReplayWorkflowHistoryFromJSON(logger *zap.Logger, reader io.Reader) error
+
+		// ReplayPartialWorkflowHistoryFromJSON executes a single decision task for the json history file upto provided
+		// lastEventID(inclusive), downloaded from the cli.
+		// To download the history file:
+		//   cadence workflow showid <workflow_id> -of <output_filename>
+		// See https://github.com/uber/cadence/blob/master/tools/cli/README.md for full documentation
+		// Use for testing the backwards compatibility of code changes and troubleshooting workflows in a debugger.
+		// The logger is an optional parameter. Defaults to the noop logger.
+		ReplayPartialWorkflowHistoryFromJSON(logger *zap.Logger, reader io.Reader, lastEventID int64) error
 	}
 
 	// WorkflowShadower retrieves and replays workflow history from Cadence service to determine if there's any nondeterministic changes in the workflow definition