fix(subflows): tag dropdown + resolution logic

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/tag-dropdown/tag-dropdown.tsx

@@ -1312,44 +1312,48 @@ export const TagDropdown: React.FC<TagDropdownProps> = ({
     if (currentLoop && isLoopBlock) {
       containingLoopBlockId = blockId
       const loopType = currentLoop.loopType || 'for'
-      const contextualTags: string[] = ['index']
-      if (loopType === 'forEach') {
-        contextualTags.push('currentItem')
-        contextualTags.push('items')
-      }
 
       const loopBlock = blocks[blockId]
       if (loopBlock) {
         const loopBlockName = loopBlock.name || loopBlock.type
+        const normalizedLoopName = normalizeName(loopBlockName)
+        const contextualTags: string[] = [`${normalizedLoopName}.index`]
+        if (loopType === 'forEach') {
+          contextualTags.push(`${normalizedLoopName}.currentItem`)
+          contextualTags.push(`${normalizedLoopName}.items`)
+        }
 
         loopBlockGroup = {
           blockName: loopBlockName,
           blockId: blockId,
           blockType: 'loop',
           tags: contextualTags,
           distance: 0,
+          isContextual: true,
         }
       }
     } else if (containingLoop) {
       const [loopId, loop] = containingLoop
       containingLoopBlockId = loopId
       const loopType = loop.loopType || 'for'
-      const contextualTags: string[] = ['index']
-      if (loopType === 'forEach') {
-        contextualTags.push('currentItem')
-        contextualTags.push('items')
-      }
 
       const containingLoopBlock = blocks[loopId]
       if (containingLoopBlock) {
         const loopBlockName = containingLoopBlock.name || containingLoopBlock.type
+        const normalizedLoopName = normalizeName(loopBlockName)
+        const contextualTags: string[] = [`${normalizedLoopName}.index`]
+        if (loopType === 'forEach') {
+          contextualTags.push(`${normalizedLoopName}.currentItem`)
+          contextualTags.push(`${normalizedLoopName}.items`)
+        }
 
         loopBlockGroup = {
           blockName: loopBlockName,
           blockId: loopId,
           blockType: 'loop',
           tags: contextualTags,
           distance: 0,
+          isContextual: true,
         }
       }
     }
@@ -1363,22 +1367,24 @@ export const TagDropdown: React.FC<TagDropdownProps> = ({
       const [parallelId, parallel] = containingParallel
       containingParallelBlockId = parallelId
       const parallelType = parallel.parallelType || 'count'
-      const contextualTags: string[] = ['index']
-      if (parallelType === 'collection') {
-        contextualTags.push('currentItem')
-        contextualTags.push('items')
-      }
 
       const containingParallelBlock = blocks[parallelId]
       if (containingParallelBlock) {
         const parallelBlockName = containingParallelBlock.name || containingParallelBlock.type
+        const normalizedParallelName = normalizeName(parallelBlockName)
+        const contextualTags: string[] = [`${normalizedParallelName}.index`]
+        if (parallelType === 'collection') {
+          contextualTags.push(`${normalizedParallelName}.currentItem`)
+          contextualTags.push(`${normalizedParallelName}.items`)
+        }
 
         parallelBlockGroup = {
           blockName: parallelBlockName,
           blockId: parallelId,
           blockType: 'parallel',
           tags: contextualTags,
           distance: 0,
+          isContextual: true,
         }
       }
     }
@@ -1645,38 +1651,29 @@ export const TagDropdown: React.FC<TagDropdownProps> = ({
   const nestedBlockTagGroups: NestedBlockTagGroup[] = useMemo(() => {
     return filteredBlockTagGroups.map((group: BlockTagGroup) => {
       const normalizedBlockName = normalizeName(group.blockName)
-
-      // Handle loop/parallel contextual tags (index, currentItem, items)
       const directTags: NestedTag[] = []
       const tagsForTree: string[] = []
 
       group.tags.forEach((tag: string) => {
         const tagParts = tag.split('.')
 
-        // Loop/parallel contextual tags without block prefix
-        if (
-          (group.blockType === 'loop' || group.blockType === 'parallel') &&
-          tagParts.length === 1
-        ) {
+        if (tagParts.length === 1) {
           directTags.push({
             key: tag,
             display: tag,
             fullTag: tag,
           })
         } else if (tagParts.length === 2) {
-          // Direct property like blockname.property
           directTags.push({
             key: tagParts[1],
             display: tagParts[1],
             fullTag: tag,
           })
         } else {
-          // Nested property - add to tree builder
           tagsForTree.push(tag)
         }
       })
 
-      // Build recursive tree from nested tags
       const nestedTags = [...directTags, ...buildNestedTagTree(tagsForTree, normalizedBlockName)]
 
       return {
@@ -1800,13 +1797,19 @@ export const TagDropdown: React.FC<TagDropdownProps> = ({
           processedTag = tag
         }
       } else if (
-        blockGroup &&
+        blockGroup?.isContextual &&
         (blockGroup.blockType === 'loop' || blockGroup.blockType === 'parallel')
       ) {
-        if (!tag.includes('.') && ['index', 'currentItem', 'items'].includes(tag)) {
-          processedTag = `${blockGroup.blockType}.${tag}`
+        const tagParts = tag.split('.')
+        if (tagParts.length === 1) {
+          processedTag = blockGroup.blockType
         } else {
-          processedTag = tag
+          const lastPart = tagParts[tagParts.length - 1]
+          if (['index', 'currentItem', 'items'].includes(lastPart)) {
+            processedTag = `${blockGroup.blockType}.${lastPart}`
+          } else {
+            processedTag = tag
+          }
         }
       }
 

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/editor/components/sub-block/components/tag-dropdown/types.ts

@@ -7,6 +7,8 @@ export interface BlockTagGroup {
   blockType: string
   tags: string[]
   distance: number
+  /** True if this is a contextual group (loop/parallel iteration context available inside the subflow) */
+  isContextual?: boolean
 }
 
 /**

apps/sim/executor/constants.ts

@@ -120,6 +120,12 @@ export const SPECIAL_REFERENCE_PREFIXES = [
   REFERENCE.PREFIX.VARIABLE,
 ] as const
 
+export const RESERVED_BLOCK_NAMES = [
+  REFERENCE.PREFIX.LOOP,
+  REFERENCE.PREFIX.PARALLEL,
+  REFERENCE.PREFIX.VARIABLE,
+] as const
+
 export const LOOP_REFERENCE = {
   ITERATION: 'iteration',
   INDEX: 'index',

apps/sim/executor/variables/resolvers/loop.test.ts

@@ -1,6 +1,7 @@
 import { loggerMock } from '@sim/testing'
 import { describe, expect, it, vi } from 'vitest'
 import type { LoopScope } from '@/executor/execution/state'
+import { InvalidFieldError } from '@/executor/utils/block-reference'
 import { LoopResolver } from './loop'
 import type { ResolutionContext } from './reference'
 
@@ -62,7 +63,12 @@ function createTestContext(
 
 describe('LoopResolver', () => {
   describe('canResolve', () => {
-    it.concurrent('should return true for loop references', () => {
+    it.concurrent('should return true for bare loop reference', () => {
+      const resolver = new LoopResolver(createTestWorkflow())
+      expect(resolver.canResolve('<loop>')).toBe(true)
+    })
+
+    it.concurrent('should return true for known loop properties', () => {
       const resolver = new LoopResolver(createTestWorkflow())
       expect(resolver.canResolve('<loop.index>')).toBe(true)
       expect(resolver.canResolve('<loop.iteration>')).toBe(true)
@@ -78,6 +84,13 @@ describe('LoopResolver', () => {
       expect(resolver.canResolve('<loop.items.0>')).toBe(true)
     })
 
+    it.concurrent('should return true for unknown loop properties (validates in resolve)', () => {
+      const resolver = new LoopResolver(createTestWorkflow())
+      expect(resolver.canResolve('<loop.results>')).toBe(true)
+      expect(resolver.canResolve('<loop.output>')).toBe(true)
+      expect(resolver.canResolve('<loop.unknownProperty>')).toBe(true)
+    })
+
     it.concurrent('should return false for non-loop references', () => {
       const resolver = new LoopResolver(createTestWorkflow())
       expect(resolver.canResolve('<block.output>')).toBe(false)
@@ -181,20 +194,34 @@ describe('LoopResolver', () => {
   })
 
   describe('edge cases', () => {
-    it.concurrent('should return undefined for invalid loop reference (missing property)', () => {
+    it.concurrent('should return context object for bare loop reference', () => {
       const resolver = new LoopResolver(createTestWorkflow())
-      const loopScope = createLoopScope({ iteration: 0 })
+      const loopScope = createLoopScope({ iteration: 2, item: 'test', items: ['a', 'b', 'c'] })
       const ctx = createTestContext('block-1', loopScope)
 
-      expect(resolver.resolve('<loop>', ctx)).toBeUndefined()
+      expect(resolver.resolve('<loop>', ctx)).toEqual({
+        index: 2,
+        currentItem: 'test',
+        items: ['a', 'b', 'c'],
+      })
+    })
+
+    it.concurrent('should return minimal context object for for-loop (no items)', () => {
+      const resolver = new LoopResolver(createTestWorkflow())
+      const loopScope = createLoopScope({ iteration: 5 })
+      const ctx = createTestContext('block-1', loopScope)
+
+      expect(resolver.resolve('<loop>', ctx)).toEqual({
+        index: 5,
+      })
     })
 
-    it.concurrent('should return undefined for unknown loop property', () => {
+    it.concurrent('should throw InvalidFieldError for unknown loop property', () => {
       const resolver = new LoopResolver(createTestWorkflow())
       const loopScope = createLoopScope({ iteration: 0 })
       const ctx = createTestContext('block-1', loopScope)
 
-      expect(resolver.resolve('<loop.unknownProperty>', ctx)).toBeUndefined()
+      expect(() => resolver.resolve('<loop.unknownProperty>', ctx)).toThrow(InvalidFieldError)
     })
 
     it.concurrent('should handle iteration index 0 correctly', () => {

apps/sim/executor/variables/resolvers/loop.ts

@@ -1,5 +1,6 @@
 import { createLogger } from '@sim/logger'
 import { isReference, parseReferencePath, REFERENCE } from '@/executor/constants'
+import { InvalidFieldError } from '@/executor/utils/block-reference'
 import { extractBaseBlockId } from '@/executor/utils/subflow-utils'
 import {
   navigatePath,
@@ -13,6 +14,8 @@ const logger = createLogger('LoopResolver')
 export class LoopResolver implements Resolver {
   constructor(private workflow: SerializedWorkflow) {}
 
+  private static KNOWN_PROPERTIES = ['iteration', 'index', 'item', 'currentItem', 'items']
+
   canResolve(reference: string): boolean {
     if (!isReference(reference)) {
       return false
@@ -27,16 +30,15 @@ export class LoopResolver implements Resolver {
 
   resolve(reference: string, context: ResolutionContext): any {
     const parts = parseReferencePath(reference)
-    if (parts.length < 2) {
-      logger.warn('Invalid loop reference - missing property', { reference })
+    if (parts.length === 0) {
+      logger.warn('Invalid loop reference', { reference })
       return undefined
     }
 
-    const [_, property, ...pathParts] = parts
+    const loopId = this.findLoopForBlock(context.currentNodeId)
     let loopScope = context.loopScope
 
     if (!loopScope) {
-      const loopId = this.findLoopForBlock(context.currentNodeId)
       if (!loopId) {
         return undefined
       }
@@ -48,6 +50,27 @@ export class LoopResolver implements Resolver {
       return undefined
     }
 
+    const isForEach = loopId ? this.isForEachLoop(loopId) : loopScope.items !== undefined
+
+    if (parts.length === 1) {
+      const result: Record<string, any> = {
+        index: loopScope.iteration,
+      }
+      if (loopScope.item !== undefined) {
+        result.currentItem = loopScope.item
+      }
+      if (loopScope.items !== undefined) {
+        result.items = loopScope.items
+      }
+      return result
+    }
+
+    const [_, property, ...pathParts] = parts
+    if (!LoopResolver.KNOWN_PROPERTIES.includes(property)) {
+      const availableFields = isForEach ? ['index', 'currentItem', 'items'] : ['index']
+      throw new InvalidFieldError('loop', property, availableFields)
+    }
+
     let value: any
     switch (property) {
       case 'iteration':
@@ -61,12 +84,8 @@ export class LoopResolver implements Resolver {
       case 'items':
         value = loopScope.items
         break
-      default:
-        logger.warn('Unknown loop property', { property })
-        return undefined
     }
 
-    // If there are additional path parts, navigate deeper
     if (pathParts.length > 0) {
       return navigatePath(value, pathParts)
     }
@@ -85,4 +104,9 @@ export class LoopResolver implements Resolver {
 
     return undefined
   }
+
+  private isForEachLoop(loopId: string): boolean {
+    const loopConfig = this.workflow.loops?.[loopId]
+    return loopConfig?.loopType === 'forEach'
+  }
 }