add wait for to foreach schema

internal/step/foreach/provider.go

@@ -43,7 +43,8 @@ var executeLifecycleStage = step.LifecycleStage{
 	RunningName:  "executing",
 	FinishedName: "finished",
 	InputFields: map[string]struct{}{
-		"items": {},
+		"items":    {},
+		"wait_for": {},
 	},
 	NextStages: []string{
 		string(StageIDOutputs),
@@ -213,6 +214,20 @@ func (r *runnableStep) Lifecycle(_ map[string]any) (step.Lifecycle[step.Lifecycl
 						nil,
 						nil,
 					),
+					"wait_for": schema.NewPropertySchema(
+						schema.NewAnySchema(),
+						schema.NewDisplayValue(
+							schema.PointerTo("Wait for condition"),
+							schema.PointerTo("Used to wait for a previous step stage to complete before running the step which is waiting."),
+							nil,
+						),
+						false,
+						nil,
+						nil,
+						nil,
+						nil,
+						nil,
+					),
 				},
 			},
 			{

workflow/workflow_test.go

@@ -3,10 +3,18 @@ package workflow_test
 import (
 	"context"
 	"errors"
+	"fmt"
 	"go.arcalot.io/assert"
 	"go.arcalot.io/lang"
 	"go.arcalot.io/log/v2"
+	"go.flow.arcalot.io/deployer"
+	deployerregistry "go.flow.arcalot.io/deployer/registry"
 	"go.flow.arcalot.io/engine/config"
+	"go.flow.arcalot.io/engine/internal/step"
+	"go.flow.arcalot.io/engine/internal/step/foreach"
+	"go.flow.arcalot.io/engine/internal/step/plugin"
+	stepregistry "go.flow.arcalot.io/engine/internal/step/registry"
+	testimpl "go.flow.arcalot.io/testdeployer"
 	"testing"
 	"time"
 
@@ -410,6 +418,241 @@ func TestWaitForStarted(t *testing.T) {
 	assert.Equals(t, outputID, "success")
 }
 
+var waitForSerialForeachWf = `
+version: v0.2.0
+input:
+  root: RootObject
+  objects:
+    RootObject:
+      id: RootObject 
+      properties: {}
+steps:
+  second_wait:
+    wait_for: !expr $.steps.first_wait.outputs.success
+    kind: foreach
+    items: 
+    - wait_time_ms: 10
+    workflow: subworkflow.yaml
+  first_wait:
+    plugin:
+      src: "n/a"
+      deployment_type: "builtin"
+    step: wait
+    input:
+      wait_time_ms: 10
+outputs:
+  success:
+    first_step_output: !expr $.steps.first_wait.outputs
+    second_step_output: !expr $.steps.second_wait.outputs
+`
+
+var waitForSerialForeachSubwf = `
+version: v0.2.0
+input:
+  root: RootObject
+  objects:
+    RootObject:
+      id: RootObject
+      properties:
+        wait_time_ms:
+          type:
+            type_id: integer
+steps:
+  wait_1:
+    plugin:
+      src: "n/a"
+      deployment_type: "builtin"
+    step: wait
+    input:
+      wait_time_ms: !expr $.input.wait_time_ms
+outputs:
+  success:
+    b: !expr $.steps.wait_1.outputs   
+`
+
+func TestWaitForSerial_Foreach(t *testing.T) {
+	// This test highlights a lack of observability in this part of
+	// Arcaflow's engine.
+	// For this test, a workflow runs two steps, where each step runs a wait
+	// step for 10 ms. The second wait step waits for the first to succeed
+	// after which it runs. Due to the wait for condition, the steps will
+	// execute serially. The total execution time for this test function
+	// should be greater than 10 ms as the first step and the foreach steps
+	// run serially.
+
+	logConfig := log.Config{
+		Level:       log.LevelInfo,
+		Destination: log.DestinationStdout,
+	}
+	logger := log.New(
+		logConfig,
+	)
+	cfg := &config.Config{
+		Log: logConfig,
+	}
+	factories := workflowFactory{
+		config: cfg,
+	}
+	deployerRegistry := deployerregistry.New(
+		deployer.Any(testimpl.NewFactory()),
+	)
+
+	pluginProvider := assert.NoErrorR[step.Provider](t)(
+		plugin.New(logger, deployerRegistry, map[string]interface{}{
+			"builtin": map[string]any{
+				"deployer_name": "test-impl",
+				"deploy_time":   "0",
+			},
+		}),
+	)
+	stepRegistry, err := stepregistry.New(
+		pluginProvider,
+		lang.Must2(foreach.New(logger, factories.createYAMLParser, factories.createWorkflow)),
+	)
+	assert.NoError(t, err)
+
+	factories.stepRegistry = stepRegistry
+	executor := lang.Must2(workflow.NewExecutor(
+		logger,
+		cfg,
+		stepRegistry,
+	))
+	wf := lang.Must2(workflow.NewYAMLConverter(stepRegistry).FromYAML([]byte(waitForSerialForeachWf)))
+	preparedWorkflow := lang.Must2(executor.Prepare(wf, map[string][]byte{
+		"subworkflow.yaml": []byte(waitForSerialForeachSubwf),
+	}))
+	startTime := time.Now() // Right before execute to not include pre-processing time.
+	outputID, outputData, err := preparedWorkflow.Execute(context.Background(), map[string]any{})
+	assert.NoError(t, err)
+	assert.Equals(t, outputID, "success")
+	stepResult := outputData.(map[interface{}]interface{})["first_step_output"]
+	assert.NotNil(t, stepResult)
+	stepResultWaitFor := stepResult.(map[string]interface{})["success"]
+	assert.NotNil(t, stepResultWaitFor)
+	stepResult2 := outputData.(map[interface{}]interface{})["second_step_output"]
+	assert.NotNil(t, stepResult2)
+	stepResultWaitFor2 := stepResult.(map[string]interface{})["success"]
+	assert.NotNil(t, stepResultWaitFor2)
+
+	duration := time.Since(startTime)
+	t.Logf("Test execution time: %s", duration)
+	if duration >= 20*time.Millisecond {
+		t.Logf("Test execution time is greater than 20 milliseconds; steps are correctly running serially due to the wait_for condition.")
+	} else {
+		t.Fatalf("Test execution time is less than 20 milliseconds; steps are not running serially.")
+	}
+}
+
+var waitForStartedForeachWf = `
+version: v0.2.0
+input:
+  root: RootObject
+  objects:
+    RootObject:
+      id: RootObject 
+      properties: {}
+steps:
+  pre_wait:
+    plugin:
+      src: "n/a"
+      deployment_type: "builtin"
+    step: wait
+    input:
+      wait_time_ms: 2
+  second_wait:
+    wait_for: !expr $.steps.first_wait.starting.started
+    kind: foreach
+    items: 
+    - wait_time_ms: 2
+    workflow: subworkflow.yaml
+  first_wait:
+    wait_for: !expr $.steps.pre_wait.outputs
+    plugin:
+      src: "n/a"
+      deployment_type: "builtin"
+    step: wait
+    input:
+      wait_time_ms: 2
+outputs:
+  success:
+    first_step_output: !expr $.steps.first_wait.outputs
+    second_step_output: !expr $.steps.second_wait.outputs
+`
+
+func TestWaitForStarted_Foreach(t *testing.T) {
+	// This test highlights a lack of observability in this part of
+	// Arcaflow's engine.
+	// For this test, the second wait step depends on the first wait
+	// step's running state being started.
+
+	logConfig := log.Config{
+		Level:       log.LevelInfo,
+		Destination: log.DestinationStdout,
+	}
+	logger := log.New(
+		logConfig,
+	)
+	cfg := &config.Config{
+		Log: logConfig,
+	}
+	factories := workflowFactory{
+		config: cfg,
+	}
+	deployerRegistry := deployerregistry.New(
+		deployer.Any(testimpl.NewFactory()),
+	)
+
+	pluginProvider := assert.NoErrorR[step.Provider](t)(
+		plugin.New(logger, deployerRegistry, map[string]interface{}{
+			"builtin": map[string]any{
+				"deployer_name": "test-impl",
+				"deploy_time":   "0",
+			},
+		}),
+	)
+	stepRegistry, err := stepregistry.New(
+		pluginProvider,
+		lang.Must2(foreach.New(logger, factories.createYAMLParser, factories.createWorkflow)),
+	)
+	assert.NoError(t, err)
+
+	factories.stepRegistry = stepRegistry
+	executor := lang.Must2(workflow.NewExecutor(
+		logger,
+		cfg,
+		stepRegistry,
+	))
+	wf := lang.Must2(workflow.NewYAMLConverter(stepRegistry).FromYAML([]byte(waitForStartedForeachWf)))
+	preparedWorkflow := lang.Must2(executor.Prepare(wf, map[string][]byte{
+		"subworkflow.yaml": []byte(waitForSerialForeachSubwf),
+	}))
+
+	outputID, _, err := preparedWorkflow.Execute(context.Background(), map[string]any{})
+	assert.NoError(t, err)
+	assert.Equals(t, outputID, "success")
+}
+
+type workflowFactory struct {
+	stepRegistry step.Registry
+	config       *config.Config
+}
+
+func (f *workflowFactory) createYAMLParser() (workflow.YAMLConverter, error) {
+	stepR := f.stepRegistry
+	if stepR == nil {
+		return nil, fmt.Errorf("YAML converter not available yet, please call the factory function after the engine has initialized")
+	}
+	return workflow.NewYAMLConverter(stepR), nil
+}
+
+func (f *workflowFactory) createWorkflow(logger log.Logger) (workflow.Executor, error) {
+	stepR := f.stepRegistry
+	if stepR == nil {
+		return nil, fmt.Errorf("YAML converter not available yet, please call the factory function after the engine has initialized")
+	}
+	return workflow.NewExecutor(logger, f.config, stepR)
+}
+
 var missingInputsFailedDeploymentWorkflowDefinition = `
 version: v0.2.0
 input: