Fix #233 - Add support to 'switch' task (#234)

* Fix #233 - Add support to 'switch' task

Signed-off-by: Ricardo Zanini <[email protected]>

* Fix headers and linters

Signed-off-by: Ricardo Zanini <[email protected]>

---------

Signed-off-by: Ricardo Zanini <[email protected]>

Author: ricardozanini

README.md

@@ -132,7 +132,7 @@ The table below lists the current state of this implementation. This table is a
 | Task Raise | ✅ |
 | Task Run | ❌ |
 | Task Set | ✅ | 
-| Task Switch | ❌ | 
+| Task Switch | ✅ | 
 | Task Try | ❌ | 
 | Task Wait | ❌ |
 | Lifecycle Events | 🟡 |
@@ -157,7 +157,7 @@ The table below lists the current state of this implementation. This table is a
 | AsyncAPI Server | ❌ |
 | AsyncAPI Outbound Message | ❌ |
 | AsyncAPI Subscription | ❌ |
-| Workflow Definition Reference | ❌ |
+| Workflow Definition Reference | ✅ |
 | Subscription Iterator | ❌ |
 
 We love contributions! Our aim is to have a complete implementation to serve as a reference or to become a project on its own to favor the CNCF Ecosystem.

impl/ctx/context.go

@@ -19,10 +19,11 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"github.com/google/uuid"
-	"github.com/serverlessworkflow/sdk-go/v3/model"
 	"sync"
 	"time"
+
+	"github.com/google/uuid"
+	"github.com/serverlessworkflow/sdk-go/v3/model"
 )
 
 var ErrWorkflowContextNotFound = errors.New("workflow context not found")

impl/expr/expr.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+
 	"github.com/itchyny/gojq"
 	"github.com/serverlessworkflow/sdk-go/v3/impl/ctx"
 	"github.com/serverlessworkflow/sdk-go/v3/model"

impl/json_pointer.go

@@ -17,9 +17,10 @@ package impl
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/serverlessworkflow/sdk-go/v3/model"
 	"reflect"
 	"strings"
+
+	"github.com/serverlessworkflow/sdk-go/v3/model"
 )
 
 func findJsonPointer(data interface{}, target string, path string) (string, bool) {

impl/json_pointer_test.go

@@ -15,9 +15,10 @@
 package impl
 
 import (
+	"testing"
+
 	"github.com/serverlessworkflow/sdk-go/v3/model"
 	"github.com/stretchr/testify/assert"
-	"testing"
 )
 
 // TestGenerateJSONPointer_SimpleTask tests a simple workflow task.
@@ -60,8 +61,8 @@ func TestGenerateJSONPointer_ForkTask(t *testing.T) {
 					Fork: model.ForkTaskConfiguration{
 						Compete: true,
 						Branches: &model.TaskList{
-							{Key: "callNurse", Task: &model.CallHTTP{Call: "http", With: model.HTTPArguments{Method: "put", Endpoint: model.NewEndpoint("https://hospital.com/api/alert/nurses")}}},
-							{Key: "callDoctor", Task: &model.CallHTTP{Call: "http", With: model.HTTPArguments{Method: "put", Endpoint: model.NewEndpoint("https://hospital.com/api/alert/doctor")}}},
+							&model.TaskItem{Key: "callNurse", Task: &model.CallHTTP{Call: "http", With: model.HTTPArguments{Method: "put", Endpoint: model.NewEndpoint("https://hospital.com/api/alert/nurses")}}},
+							&model.TaskItem{Key: "callDoctor", Task: &model.CallHTTP{Call: "http", With: model.HTTPArguments{Method: "put", Endpoint: model.NewEndpoint("https://hospital.com/api/alert/doctor")}}},
 						},
 					},
 				},
@@ -85,12 +86,12 @@ func TestGenerateJSONPointer_DeepNestedTask(t *testing.T) {
 					Fork: model.ForkTaskConfiguration{
 						Compete: false,
 						Branches: &model.TaskList{
-							{
+							&model.TaskItem{
 								Key: "branchA",
 								Task: &model.ForkTask{
 									Fork: model.ForkTaskConfiguration{
 										Branches: &model.TaskList{
-											{
+											&model.TaskItem{
 												Key:  "deepTask",
 												Task: &model.SetTask{Set: map[string]interface{}{"result": "done"}},
 											},

impl/runner.go

@@ -17,9 +17,10 @@ package impl
 import (
 	"context"
 	"fmt"
+	"time"
+
 	"github.com/serverlessworkflow/sdk-go/v3/impl/ctx"
 	"github.com/serverlessworkflow/sdk-go/v3/model"
-	"time"
 )
 
 var _ WorkflowRunner = &workflowRunnerImpl{}

impl/runner_test.go

@@ -17,13 +17,14 @@ package impl
 import (
 	"context"
 	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
 	"github.com/serverlessworkflow/sdk-go/v3/impl/ctx"
 	"github.com/serverlessworkflow/sdk-go/v3/model"
 	"github.com/serverlessworkflow/sdk-go/v3/parser"
 	"github.com/stretchr/testify/assert"
-	"os"
-	"path/filepath"
-	"testing"
 )
 
 type taskSupportOpts func(*workflowRunnerImpl)
@@ -407,3 +408,51 @@ func TestForTaskRunner_Run(t *testing.T) {
 	})
 
 }
+
+func TestSwitchTaskRunner_Run(t *testing.T) {
+	t.Run("Color is red", func(t *testing.T) {
+		workflowPath := "./testdata/switch_match.yaml"
+		input := map[string]interface{}{
+			"color": "red",
+		}
+		expectedOutput := map[string]interface{}{
+			"colors": []interface{}{"red"},
+		}
+		runWorkflowTest(t, workflowPath, input, expectedOutput)
+	})
+
+	t.Run("Color is green", func(t *testing.T) {
+		workflowPath := "./testdata/switch_match.yaml"
+		input := map[string]interface{}{
+			"color": "green",
+		}
+		expectedOutput := map[string]interface{}{
+			"colors": []interface{}{"green"},
+		}
+		runWorkflowTest(t, workflowPath, input, expectedOutput)
+	})
+
+	t.Run("Color is blue", func(t *testing.T) {
+		workflowPath := "./testdata/switch_match.yaml"
+		input := map[string]interface{}{
+			"color": "blue",
+		}
+		expectedOutput := map[string]interface{}{
+			"colors": []interface{}{"blue"},
+		}
+		runWorkflowTest(t, workflowPath, input, expectedOutput)
+	})
+}
+
+func TestSwitchTaskRunner_DefaultCase(t *testing.T) {
+	t.Run("Color is unknown, should match default", func(t *testing.T) {
+		workflowPath := "./testdata/switch_with_default.yaml"
+		input := map[string]interface{}{
+			"color": "yellow",
+		}
+		expectedOutput := map[string]interface{}{
+			"colors": []interface{}{"default"},
+		}
+		runWorkflowTest(t, workflowPath, input, expectedOutput)
+	})
+}

impl/task_runner.go

@@ -16,9 +16,10 @@ package impl
 
 import (
 	"context"
+	"time"
+
 	"github.com/serverlessworkflow/sdk-go/v3/impl/ctx"
 	"github.com/serverlessworkflow/sdk-go/v3/model"
-	"time"
 )
 
 var _ TaskRunner = &SetTaskRunner{}

impl/task_runner_do.go

@@ -16,9 +16,10 @@ package impl
 
 import (
 	"fmt"
+	"time"
+
 	"github.com/serverlessworkflow/sdk-go/v3/impl/ctx"
 	"github.com/serverlessworkflow/sdk-go/v3/model"
-	"time"
 )
 
 // NewTaskRunner creates a TaskRunner instance based on the task type.
@@ -86,6 +87,24 @@ func (d *DoTaskRunner) runTasks(input interface{}, tasks *model.TaskList) (outpu
 		}
 
 		d.TaskSupport.SetTaskStatus(currentTask.Key, ctx.PendingStatus)
+
+		// Check if this task is a SwitchTask and handle it
+		if switchTask, ok := currentTask.Task.(*model.SwitchTask); ok {
+			flowDirective, err := d.evaluateSwitchTask(input, currentTask.Key, switchTask)
+			if err != nil {
+				d.TaskSupport.SetTaskStatus(currentTask.Key, ctx.FaultedStatus)
+				return output, err
+			}
+			d.TaskSupport.SetTaskStatus(currentTask.Key, ctx.CompletedStatus)
+
+			// Process FlowDirective: update idx/currentTask accordingly
+			idx, currentTask = tasks.KeyAndIndex(flowDirective.Value)
+			if currentTask == nil {
+				return nil, fmt.Errorf("flow directive target '%s' not found", flowDirective.Value)
+			}
+			continue
+		}
+
 		runner, err := NewTaskRunner(currentTask.Key, currentTask.Task, d.TaskSupport)
 		if err != nil {
 			return output, err
@@ -116,6 +135,32 @@ func (d *DoTaskRunner) shouldRunTask(input interface{}, task *model.TaskItem) (b
 	return true, nil
 }
 
+func (d *DoTaskRunner) evaluateSwitchTask(input interface{}, taskKey string, switchTask *model.SwitchTask) (*model.FlowDirective, error) {
+	var defaultThen *model.FlowDirective
+	for _, switchItem := range switchTask.Switch {
+		for _, switchCase := range switchItem {
+			if switchCase.When == nil {
+				defaultThen = switchCase.Then
+				continue
+			}
+			result, err := traverseAndEvaluateBool(model.NormalizeExpr(switchCase.When.String()), input, d.TaskSupport.GetContext())
+			if err != nil {
+				return nil, model.NewErrExpression(err, taskKey)
+			}
+			if result {
+				if switchCase.Then == nil {
+					return nil, model.NewErrExpression(fmt.Errorf("missing 'then' directive in matched switch case"), taskKey)
+				}
+				return switchCase.Then, nil
+			}
+		}
+	}
+	if defaultThen != nil {
+		return defaultThen, nil
+	}
+	return nil, model.NewErrExpression(fmt.Errorf("no matching switch case"), taskKey)
+}
+
 // runTask executes an individual task.
 func (d *DoTaskRunner) runTask(input interface{}, runner TaskRunner, task *model.TaskBase) (output interface{}, err error) {
 	taskName := runner.GetTaskName()

impl/task_runner_for.go

@@ -16,10 +16,11 @@ package impl
 
 import (
 	"fmt"
-	"github.com/serverlessworkflow/sdk-go/v3/impl/expr"
-	"github.com/serverlessworkflow/sdk-go/v3/model"
 	"reflect"
 	"strings"
+
+	"github.com/serverlessworkflow/sdk-go/v3/impl/expr"
+	"github.com/serverlessworkflow/sdk-go/v3/model"
 )
 
 const (

impl/task_runner_raise.go

@@ -16,6 +16,7 @@ package impl
 
 import (
 	"fmt"
+
 	"github.com/serverlessworkflow/sdk-go/v3/model"
 )
 

impl/task_runner_raise_test.go

@@ -17,9 +17,10 @@ package impl
 import (
 	"encoding/json"
 	"errors"
-	"github.com/serverlessworkflow/sdk-go/v3/impl/ctx"
 	"testing"
 
+	"github.com/serverlessworkflow/sdk-go/v3/impl/ctx"
+
 	"github.com/serverlessworkflow/sdk-go/v3/model"
 	"github.com/stretchr/testify/assert"
 )

impl/task_runner_set.go

@@ -16,6 +16,7 @@ package impl
 
 import (
 	"fmt"
+
 	"github.com/serverlessworkflow/sdk-go/v3/model"
 )
 

impl/testdata/switch_match.yaml

@@ -0,0 +1,43 @@
+# Copyright 2025 The Serverless Workflow Specification Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+document:
+  dsl: '1.0.0'
+  namespace: default
+  name: switch-match
+  version: '1.0.0'
+do:
+  - switchColor:
+      switch:
+        - red:
+            when: '.color == "red"'
+            then: setRed
+        - green:
+            when: '.color == "green"'
+            then: setGreen
+        - blue:
+            when: '.color == "blue"'
+            then: setBlue
+  - setRed:
+      set:
+        colors: '${ .colors + [ "red" ] }'
+      then: end
+  - setGreen:
+      set:
+        colors: '${ .colors + [ "green" ] }'
+      then: end
+  - setBlue:
+      set:
+        colors: '${ .colors + [ "blue" ] }'
+      then: end

impl/testdata/switch_with_default.yaml

@@ -0,0 +1,43 @@
+# Copyright 2025 The Serverless Workflow Specification Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+document:
+  dsl: '1.0.0'
+  namespace: default
+  name: switch-with-default
+  version: '1.0.0'
+
+do:
+  - switchColor:
+      switch:
+        - red:
+            when: '.color == "red"'
+            then: setRed
+        - green:
+            when: '.color == "green"'
+            then: setGreen
+        - fallback:
+            then: setDefault
+  - setRed:
+      set:
+        colors: '${ .colors + [ "red" ] }'
+      then: end
+  - setGreen:
+      set:
+        colors: '${ .colors + [ "green" ] }'
+      then: end
+  - setDefault:
+      set:
+        colors: '${ .colors + [ "default" ] }'
+      then: end

impl/utils.go

@@ -16,6 +16,7 @@ package impl
 
 import (
 	"context"
+
 	"github.com/serverlessworkflow/sdk-go/v3/impl/expr"
 	"github.com/serverlessworkflow/sdk-go/v3/model"
 )