fix: if/skip_if guards no longer mark skipped steps as executed (closes #362)

Add Skipped bool to StepResult. When a SkippableStep bypasses execution,
the pipeline executor detects result.Skipped and skips MergeStepOutput,
so StepExecuted("name") correctly returns false for guard-skipped steps.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: intel352

interfaces/pipeline.go

@@ -108,6 +108,10 @@ type StepResult struct {
 
 	// Stop indicates the pipeline should stop after this step (success).
 	Stop bool
+
+	// Skipped indicates the step was bypassed by a guard (skip_if or if).
+	// When true, the pipeline executor will not record this step in StepOutputs.
+	Skipped bool
 }
 
 // PipelineStep is a single composable unit of work in a pipeline.

module/pipeline_executor.go

@@ -224,6 +224,18 @@ func (p *Pipeline) Execute(ctx context.Context, triggerData map[string]any) (*Pi
 			}
 		}
 
+		// Guard-skipped steps are not recorded in StepOutputs.
+		if result != nil && result.Skipped {
+			logger.Info("Step skipped by guard", "pipeline", p.Name, "step", step.Name(), "elapsed", elapsed)
+			p.recordEvent(ctx, "step.skipped", map[string]any{
+				"step_name": step.Name(),
+				"reason":    result.Output["reason"],
+				"elapsed":   elapsed.String(),
+			})
+			i++
+			continue
+		}
+
 		logger.Info("Step completed", "pipeline", p.Name, "step", step.Name(), "elapsed", elapsed)
 
 		// Record step.completed

module/pipeline_step_skip.go

@@ -87,6 +87,7 @@ func isTruthy(val string) bool {
 // skippedResult builds the standard output for a step that was skipped by a guard.
 func skippedResult(reason string) *interfaces.StepResult {
 	return &interfaces.StepResult{
+		Skipped: true,
 		Output: map[string]any{
 			"skipped": true,
 			"reason":  reason,

wftest/harness_test.go

@@ -204,3 +204,77 @@ pipelines:
 		t.Error("expected error for missing pipeline")
 	}
 }
+
+func TestSkipIf_StepNotTrackedAsExecuted(t *testing.T) {
+	h := wftest.New(t, wftest.WithYAML(`
+pipelines:
+  test:
+    steps:
+      - name: always_runs
+        type: step.set
+        config:
+          values:
+            flag: "true"
+      - name: skipped_step
+        type: step.set
+        skip_if: '{{ eq .flag "true" }}'
+        config:
+          values:
+            should_not_run: true
+      - name: final
+        type: step.set
+        config:
+          values:
+            done: true
+`))
+	result := h.ExecutePipeline("test", nil)
+	if result.Error != nil {
+		t.Fatal(result.Error)
+	}
+	if !result.StepExecuted("always_runs") {
+		t.Error("always_runs should have been executed")
+	}
+	if result.StepExecuted("skipped_step") {
+		t.Error("skipped_step should NOT have been executed (skip_if was true)")
+	}
+	if !result.StepExecuted("final") {
+		t.Error("final should have been executed")
+	}
+}
+
+func TestIf_StepNotTrackedWhenConditionFalse(t *testing.T) {
+	h := wftest.New(t, wftest.WithYAML(`
+pipelines:
+  test:
+    steps:
+      - name: set_flag
+        type: step.set
+        config:
+          values:
+            flag: "true"
+      - name: conditional_step
+        type: step.set
+        if: '{{ eq .flag "false" }}'
+        config:
+          values:
+            should_not_run: true
+      - name: final
+        type: step.set
+        config:
+          values:
+            done: true
+`))
+	result := h.ExecutePipeline("test", nil)
+	if result.Error != nil {
+		t.Fatal(result.Error)
+	}
+	if !result.StepExecuted("set_flag") {
+		t.Error("set_flag should have been executed")
+	}
+	if result.StepExecuted("conditional_step") {
+		t.Error("conditional_step should NOT have been executed (if condition was false)")
+	}
+	if !result.StepExecuted("final") {
+		t.Error("final should have been executed")
+	}
+}