Fix executor_test.go: ErrorIs arg order, wrong target, and data races

- TestNewParallelExecutorFailed: fix assert.ErrorIs argument order
- TestNewParallelExecutorCanceled: check for context.Canceled (not the
  executor error) since NewParallelExecutor returns ctx.Err() when
  context is cancelled; use atomic counter to fix data race
- TestNewParallelExecutor: use atomic counters to fix data race with
  concurrent goroutines

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/common/executor_test.go

@@ -3,6 +3,7 @@ package common
 import (
 	"context"
 	"errors"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -80,37 +81,40 @@ func TestNewParallelExecutor(t *testing.T) {
 
 	ctx := context.Background()
 
-	count := 0
-	activeCount := 0
-	maxCount := 0
+	var count atomic.Int32
+	var activeCount atomic.Int32
+	var maxCount atomic.Int32
 	emptyWorkflow := NewPipelineExecutor(func(_ context.Context) error {
-		count++
+		count.Add(1)
 
-		activeCount++
-		if activeCount > maxCount {
-			maxCount = activeCount
+		cur := activeCount.Add(1)
+		for {
+			old := maxCount.Load()
+			if cur <= old || maxCount.CompareAndSwap(old, cur) {
+				break
+			}
 		}
 		time.Sleep(2 * time.Second)
-		activeCount--
+		activeCount.Add(-1)
 
 		return nil
 	})
 
 	err := NewParallelExecutor(2, emptyWorkflow, emptyWorkflow, emptyWorkflow)(ctx)
 
-	assert.Equal(3, count, "should run all 3 executors")
-	assert.Equal(2, maxCount, "should run at most 2 executors in parallel")
+	assert.Equal(int32(3), count.Load(), "should run all 3 executors")
+	assert.Equal(int32(2), maxCount.Load(), "should run at most 2 executors in parallel")
 	require.NoError(t, err)
 
 	// Reset to test running the executor with 0 parallelism
-	count = 0
-	activeCount = 0
-	maxCount = 0
+	count.Store(0)
+	activeCount.Store(0)
+	maxCount.Store(0)
 
 	errSingle := NewParallelExecutor(0, emptyWorkflow, emptyWorkflow, emptyWorkflow)(ctx)
 
-	assert.Equal(3, count, "should run all 3 executors")
-	assert.Equal(1, maxCount, "should run at most 1 executors in parallel")
+	assert.Equal(int32(3), count.Load(), "should run all 3 executors")
+	assert.Equal(int32(1), maxCount.Load(), "should run at most 1 executors in parallel")
 	require.NoError(t, errSingle)
 }
 
@@ -127,7 +131,7 @@ func TestNewParallelExecutorFailed(t *testing.T) {
 	})
 	err := NewParallelExecutor(1, errorWorkflow)(ctx)
 	assert.Equal(1, count)
-	assert.ErrorIs(context.Canceled, err)
+	assert.ErrorIs(err, context.Canceled)
 }
 
 func TestNewParallelExecutorCanceled(t *testing.T) {
@@ -136,18 +140,16 @@ func TestNewParallelExecutorCanceled(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
 
-	errExpected := errors.New("fake error")
-
-	count := 0
+	var count atomic.Int32
 	successWorkflow := NewPipelineExecutor(func(_ context.Context) error {
-		count++
+		count.Add(1)
 		return nil
 	})
 	errorWorkflow := NewPipelineExecutor(func(_ context.Context) error {
-		count++
-		return errExpected
+		count.Add(1)
+		return errors.New("fake error")
 	})
 	err := NewParallelExecutor(3, errorWorkflow, successWorkflow, successWorkflow)(ctx)
-	assert.Equal(3, count)
-	assert.ErrorIs(errExpected, err)
+	assert.Equal(int32(3), count.Load())
+	assert.ErrorIs(err, context.Canceled)
 }