refactor: remove updateConnection operation (breaking change)

Remove UpdateConnectionOperation completely as planned for v2.16.0.
This is a breaking change - users should use removeConnection + addConnection
or the new rewireConnection operation instead.

Changes:
- Remove UpdateConnectionOperation type definition
- Remove validateUpdateConnection and applyUpdateConnection methods
- Remove updateConnection cases from validation/apply switches
- Remove updateConnection tests (4 tests)
- Remove UpdateConnectionOperation import from tests

All 137 tests passing.

Related: #272 Phase 1

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/services/workflow-diff-engine.ts

@@ -20,7 +20,6 @@ import {
   DisableNodeOperation,
   AddConnectionOperation,
   RemoveConnectionOperation,
-  UpdateConnectionOperation,
   RewireConnectionOperation,
   UpdateSettingsOperation,
   UpdateNameOperation,
@@ -224,8 +223,6 @@ export class WorkflowDiffEngine {
         return this.validateAddConnection(workflow, operation);
       case 'removeConnection':
         return this.validateRemoveConnection(workflow, operation);
-      case 'updateConnection':
-        return this.validateUpdateConnection(workflow, operation);
       case 'rewireConnection':
         return this.validateRewireConnection(workflow, operation as RewireConnectionOperation);
       case 'updateSettings':
@@ -271,9 +268,6 @@ export class WorkflowDiffEngine {
       case 'removeConnection':
         this.applyRemoveConnection(workflow, operation);
         break;
-      case 'updateConnection':
-        this.applyUpdateConnection(workflow, operation);
-        break;
       case 'rewireConnection':
         this.applyRewireConnection(workflow, operation as RewireConnectionOperation);
         break;
@@ -461,40 +455,6 @@ export class WorkflowDiffEngine {
     return null;
   }
 
-  private validateUpdateConnection(workflow: Workflow, operation: UpdateConnectionOperation): string | null {
-    const sourceNode = this.findNode(workflow, operation.source, operation.source);
-    const targetNode = this.findNode(workflow, operation.target, operation.target);
-
-    if (!sourceNode) {
-      return `Source node not found: ${operation.source}`;
-    }
-    if (!targetNode) {
-      return `Target node not found: ${operation.target}`;
-    }
-
-    // Check if connection exists to update
-    const existingConnections = workflow.connections[sourceNode.name];
-    if (!existingConnections) {
-      return `No connections found from "${sourceNode.name}"`;
-    }
-
-    // Check if any connection to target exists
-    let hasConnection = false;
-    Object.values(existingConnections).forEach(outputs => {
-      outputs.forEach(connections => {
-        if (connections.some(c => c.node === targetNode.name)) {
-          hasConnection = true;
-        }
-      });
-    });
-
-    if (!hasConnection) {
-      return `No connection exists from "${sourceNode.name}" to "${targetNode.name}"`;
-    }
-
-    return null;
-  }
-
   private validateRewireConnection(workflow: Workflow, operation: RewireConnectionOperation): string | null {
     // Validate source node exists
     const sourceNode = this.findNode(workflow, operation.source, operation.source);
@@ -743,53 +703,6 @@ export class WorkflowDiffEngine {
     }
   }
 
-  private applyUpdateConnection(workflow: Workflow, operation: UpdateConnectionOperation): void {
-    // Validate that updates object exists and is an object
-    if (!operation.updates || typeof operation.updates !== 'object') {
-      throw new Error(
-        `updateConnection operation requires 'updates' object.\n\n` +
-        `You provided: ${JSON.stringify(operation, null, 2)}\n\n` +
-        `The 'updates' property is missing or invalid. ` +
-        `This operation modifies connection properties (output type, input type, indices), ` +
-        `not connection targets.\n\n` +
-        `Correct format:\n` +
-        `{\n` +
-        `  type: "updateConnection",\n` +
-        `  source: "IF",\n` +
-        `  target: "EmailNode",\n` +
-        `  updates: {\n` +
-        `    sourceOutput: "false"  // Change from one output to another\n` +
-        `  }\n` +
-        `}\n\n` +
-        `💡 Note: If you want to change which node a connection goes to, ` +
-        `use removeConnection + addConnection instead:\n` +
-        `[\n` +
-        `  {type: "removeConnection", source: "${operation.source}", target: "${operation.target}"},\n` +
-        `  {type: "addConnection", source: "${operation.source}", target: "NewTarget"}\n` +
-        `]`
-      );
-    }
-
-    // Implement as remove + add with the updated properties
-    this.applyRemoveConnection(workflow, {
-      type: 'removeConnection',
-      source: operation.source,
-      target: operation.target,
-      sourceOutput: operation.updates.sourceOutput,
-      targetInput: operation.updates.targetInput
-    });
-
-    this.applyAddConnection(workflow, {
-      type: 'addConnection',
-      source: operation.source,
-      target: operation.target,
-      sourceOutput: operation.updates.sourceOutput,
-      targetInput: operation.updates.targetInput,
-      sourceIndex: operation.updates.sourceIndex,
-      targetIndex: operation.updates.targetIndex
-    });
-  }
-
   /**
    * Rewire a connection from one target to another
    * This is a semantic wrapper around removeConnection + addConnection

src/types/workflow-diff.ts

@@ -78,18 +78,6 @@ export interface RemoveConnectionOperation extends DiffOperation {
   ignoreErrors?: boolean; // If true, don't fail when connection doesn't exist (useful for cleanup)
 }
 
-export interface UpdateConnectionOperation extends DiffOperation {
-  type: 'updateConnection';
-  source: string;
-  target: string;
-  updates: {
-    sourceOutput?: string;
-    targetInput?: string;
-    sourceIndex?: number;
-    targetIndex?: number;
-  };
-}
-
 export interface RewireConnectionOperation extends DiffOperation {
   type: 'rewireConnection';
   source: string;      // Source node name or ID
@@ -155,7 +143,6 @@ export type WorkflowDiffOperation =
   | DisableNodeOperation
   | AddConnectionOperation
   | RemoveConnectionOperation
-  | UpdateConnectionOperation
   | RewireConnectionOperation
   | UpdateSettingsOperation
   | UpdateNameOperation
@@ -204,8 +191,8 @@ export function isNodeOperation(op: WorkflowDiffOperation): op is
 }
 
 export function isConnectionOperation(op: WorkflowDiffOperation): op is
-  AddConnectionOperation | RemoveConnectionOperation | UpdateConnectionOperation | RewireConnectionOperation | CleanStaleConnectionsOperation | ReplaceConnectionsOperation {
-  return ['addConnection', 'removeConnection', 'updateConnection', 'rewireConnection', 'cleanStaleConnections', 'replaceConnections'].includes(op.type);
+  AddConnectionOperation | RemoveConnectionOperation | RewireConnectionOperation | CleanStaleConnectionsOperation | ReplaceConnectionsOperation {
+  return ['addConnection', 'removeConnection', 'rewireConnection', 'cleanStaleConnections', 'replaceConnections'].includes(op.type);
 }
 
 export function isMetadataOperation(op: WorkflowDiffOperation): op is 

tests/unit/services/workflow-diff-engine.test.ts

@@ -12,7 +12,6 @@ import {
   DisableNodeOperation,
   AddConnectionOperation,
   RemoveConnectionOperation,
-  UpdateConnectionOperation,
   UpdateSettingsOperation,
   UpdateNameOperation,
   AddTagOperation,
@@ -774,98 +773,6 @@ describe('WorkflowDiffEngine', () => {
     });
   });
 
-  describe('UpdateConnection Operation', () => {
-    it('should update connection properties', async () => {
-      // Add an IF node with multiple outputs
-      const addNodeOp: AddNodeOperation = {
-        type: 'addNode',
-        node: {
-          name: 'IF',
-          type: 'n8n-nodes-base.if',
-          position: [600, 300]
-        }
-      };
-
-      const addConnectionOp: AddConnectionOperation = {
-        type: 'addConnection',
-        source: 'IF',
-        target: 'slack-1',
-        sourceOutput: 'true'
-      };
-
-      const updateConnectionOp: UpdateConnectionOperation = {
-        type: 'updateConnection',
-        source: 'IF',
-        target: 'slack-1',
-        updates: {
-          sourceOutput: 'false',
-          sourceIndex: 0,
-          targetIndex: 0
-        }
-      };
-
-      const request: WorkflowDiffRequest = {
-        id: 'test-workflow',
-        operations: [addNodeOp, addConnectionOp, updateConnectionOp]
-      };
-
-      const result = await diffEngine.applyDiff(baseWorkflow, request);
-      
-      expect(result.success).toBe(true);
-      // After update, the connection should be on 'false' output only
-      expect(result.workflow!.connections['IF'].false).toBeDefined();
-      expect(result.workflow!.connections['IF'].false[0][0].node).toBe('Slack');
-      // The 'true' output should still have the original connection
-      // because updateConnection removes using the NEW output values, not the old ones
-      expect(result.workflow!.connections['IF'].true).toBeDefined();
-      expect(result.workflow!.connections['IF'].true[0][0].node).toBe('Slack');
-    });
-
-    it('should reject updateConnection without updates object (Issue #272, #204)', async () => {
-      const operation: any = {
-        type: 'updateConnection',
-        source: 'Webhook',
-        target: 'HTTP Request'
-        // Missing updates object - should fail with helpful error
-      };
-
-      const request: WorkflowDiffRequest = {
-        id: 'test-workflow',
-        operations: [operation]
-      };
-
-      const result = await diffEngine.applyDiff(baseWorkflow, request);
-
-      expect(result.success).toBe(false);
-      expect(result.errors).toBeDefined();
-      expect(result.errors![0].message).toContain('updates');
-      expect(result.errors![0].message).toContain('object');
-      // Should include helpful guidance
-      expect(result.errors![0].message).toContain('removeConnection');
-      expect(result.errors![0].message).toContain('addConnection');
-    });
-
-    it('should reject updateConnection with invalid updates type', async () => {
-      const operation: any = {
-        type: 'updateConnection',
-        source: 'Webhook',
-        target: 'HTTP Request',
-        updates: 'invalid'  // Should be object, not string
-      };
-
-      const request: WorkflowDiffRequest = {
-        id: 'test-workflow',
-        operations: [operation]
-      };
-
-      const result = await diffEngine.applyDiff(baseWorkflow, request);
-
-      expect(result.success).toBe(false);
-      expect(result.errors).toBeDefined();
-      expect(result.errors![0].message).toContain('updates');
-      expect(result.errors![0].message).toContain('object');
-    });
-  });
 
   describe('RewireConnection Operation (Phase 1)', () => {
     it('should rewire connection from one target to another', async () => {
@@ -3673,47 +3580,6 @@ describe('WorkflowDiffEngine', () => {
         expect(result.workflow).toBeUndefined();
       });
 
-      it('should handle updateConnection with complex output configurations', async () => {
-        const workflow = JSON.parse(JSON.stringify(baseWorkflow));
-
-        // Add IF node
-        workflow.nodes.push({
-          id: 'if-1',
-          name: 'IF',
-          type: 'n8n-nodes-base.if',
-          typeVersion: 1,
-          position: [600, 400],
-          parameters: {}
-        });
-
-        // Add connection on 'true' output
-        workflow.connections['IF'] = {
-          'true': [[
-            { node: 'Slack', type: 'main', index: 0 }
-          ]]
-        };
-
-        const operations: UpdateConnectionOperation[] = [{
-          type: 'updateConnection',
-          source: 'IF',
-          target: 'Slack',
-          updates: {
-            sourceOutput: 'false',
-            targetInput: 'main',
-            sourceIndex: 0,
-            targetIndex: 0
-          }
-        }];
-
-        const request: WorkflowDiffRequest = {
-          id: 'test-workflow',
-          operations
-        };
-
-        const result = await diffEngine.applyDiff(workflow, request);
-
-        expect(result.success).toBe(true);
-      });
 
       it('should handle addConnection with all optional parameters specified', async () => {
         const workflow = JSON.parse(JSON.stringify(baseWorkflow));