fix(conditional): don't error in condition blocks when no conditions are satisfied (#2243)

* fix(conditional): don't error in condition blocks when no conditions are satisfied

* updated docs

Author: waleedlatif1

apps/docs/content/docs/en/blocks/condition.mdx

@@ -135,7 +135,7 @@ Function (Process) → Condition (account_type === 'enterprise') → Advanced or
 ## Best Practices
 
 - **Order conditions correctly**: Place more specific conditions before general ones to ensure specific logic takes precedence over fallbacks
-- **Include a default condition**: Add a catch-all condition (`true`) as the last condition to handle unmatched cases and prevent workflow execution from getting stuck
+- **Use the else branch when needed**: If no conditions match and the else branch is not connected, the workflow branch will end gracefully. Connect the else branch if you need a fallback path for unmatched cases
 - **Keep expressions simple**: Use clear, straightforward boolean expressions for better readability and easier debugging
 - **Document your conditions**: Add descriptions to explain the purpose of each condition for better team collaboration and maintenance
 - **Test edge cases**: Verify conditions handle boundary values correctly by testing with values at the edges of your condition ranges

apps/sim/executor/handlers/condition/condition-handler.test.ts

@@ -365,7 +365,7 @@ describe('ConditionBlockHandler', () => {
     )
   })
 
-  it('should throw error if no condition matches and no else exists', async () => {
+  it('should return no-match result if no condition matches and no else exists', async () => {
     const conditions = [
       { id: 'cond1', title: 'if', value: 'false' },
       { id: 'cond2', title: 'else if', value: 'context.value === 99' },
@@ -392,9 +392,15 @@ describe('ConditionBlockHandler', () => {
       .mockReturnValueOnce('false')
       .mockReturnValueOnce('context.value === 99')
 
-    await expect(handler.execute(mockContext, mockBlock, inputs)).rejects.toThrow(
-      `No matching path found for condition block "${mockBlock.metadata?.name}", and no 'else' block exists.`
-    )
+    const result = await handler.execute(mockContext, mockBlock, inputs)
+
+    // Should return success with no path selected (branch ends gracefully)
+    expect((result as any).conditionResult).toBe(false)
+    expect((result as any).selectedPath).toBeNull()
+    expect((result as any).selectedConditionId).toBeNull()
+    expect((result as any).selectedOption).toBeNull()
+    // Decision should not be set when no condition matches
+    expect(mockContext.decisions.condition.has(mockBlock.id)).toBe(false)
   })
 
   it('falls back to else path when loop context data is unavailable', async () => {

apps/sim/executor/handlers/condition/condition-handler.ts

@@ -87,6 +87,17 @@ export class ConditionBlockHandler implements BlockHandler {
       block
     )
 
+    // Handle case where no condition matched and no else exists - branch ends gracefully
+    if (!selectedConnection || !selectedCondition) {
+      return {
+        ...((sourceOutput as any) || {}),
+        conditionResult: false,
+        selectedPath: null,
+        selectedConditionId: null,
+        selectedOption: null,
+      }
+    }
+
     const targetBlock = ctx.workflow?.blocks.find((b) => b.id === selectedConnection?.target)
     if (!targetBlock) {
       throw new Error(`Target block ${selectedConnection?.target} not found`)
@@ -145,8 +156,8 @@ export class ConditionBlockHandler implements BlockHandler {
     ctx: ExecutionContext,
     block: SerializedBlock
   ): Promise<{
-    selectedConnection: { target: string; sourceHandle?: string }
-    selectedCondition: { id: string; title: string; value: string }
+    selectedConnection: { target: string; sourceHandle?: string } | null
+    selectedCondition: { id: string; title: string; value: string } | null
   }> {
     for (const condition of conditions) {
       if (condition.title === CONDITION.ELSE_TITLE) {
@@ -185,14 +196,16 @@ export class ConditionBlockHandler implements BlockHandler {
       if (elseConnection) {
         return { selectedConnection: elseConnection, selectedCondition: elseCondition }
       }
-      throw new Error(
-        `No path found for condition block "${block.metadata?.name}", and 'else' connection missing.`
-      )
+      // Else exists but has no connection - treat as no match, branch ends
+      logger.info(`No condition matched and else has no connection - branch ending`, {
+        blockId: block.id,
+      })
+      return { selectedConnection: null, selectedCondition: null }
     }
 
-    throw new Error(
-      `No matching path found for condition block "${block.metadata?.name}", and no 'else' block exists.`
-    )
+    // No condition matched and no else exists - branch ends gracefully
+    logger.info(`No condition matched and no else block - branch ending`, { blockId: block.id })
+    return { selectedConnection: null, selectedCondition: null }
   }
 
   private findConnectionForCondition(