fix: Use existing type for JSON/YAML union and add explanatory comments to Emit task form

packages/open-workflow-diagram-editor/src/core/schemaToFormFields.ts

@@ -15,6 +15,7 @@
  */
 
 import type { DereferencedSchema } from "./schemaFilter";
+import type { ContentFormat } from "./workflowSdk";
 
 /**
  * A single form field descriptor produced by walking a task's JSON Schema.
@@ -107,7 +108,7 @@ export interface MapField extends FieldBase {
 
 export interface JsonField extends FieldBase {
   kind: "json";
-  format: "json" | "yaml";
+  format: ContentFormat;
 }
 
 export interface OneOfField extends FieldBase {
@@ -313,7 +314,7 @@ export function schemaToFormFields(
   defs?: Record<string, unknown>,
   requiredSet?: Set<string>,
   path = "",
-  format: "json" | "yaml" = "yaml",
+  format: ContentFormat = "yaml",
 ): FormFieldDescriptor[] {
   const fields: FormFieldDescriptor[] = [];
 
@@ -636,7 +637,7 @@ function buildOneOfVariants(
   candidates: unknown[],
   defs: Record<string, unknown> | undefined,
   parentPath: string,
-  format: "json" | "yaml" = "yaml",
+  format: ContentFormat = "yaml",
 ): OneOfVariant[] {
   const leafPath = parentPath || "__leaf__";
 

packages/open-workflow-diagram-editor/src/core/schemaWalker.ts

@@ -17,6 +17,7 @@
 import { GraphNodeType } from "@openworkflowspec/sdk";
 import { getSchemaForDefinition } from "./schemaFilter";
 import { schemaToFormFields, FormFieldDescriptor } from "./schemaToFormFields";
+import type { ContentFormat } from "./workflowSdk";
 
 // ---------------------------------------------------------------------------
 // Node-type → schema definition-name mapping
@@ -60,7 +61,7 @@ const _fieldCache = new Map<string, FormFieldDescriptor[]>();
  */
 export function getFormFieldsForNodeType(
   nodeType: string,
-  format: "json" | "yaml" = "yaml",
+  format: ContentFormat = "yaml",
 ): FormFieldDescriptor[] {
   const cacheKey = `${nodeType}:${format}`;
   const cached = _fieldCache.get(cacheKey);

packages/open-workflow-diagram-editor/src/side-panel/forms/customFields/StringControl.tsx

@@ -85,6 +85,12 @@ function SingleLineStringControl({ field, id }: StringControlProps) {
       }
     }
     setInputValue(typeof live === "string" ? live : "");
+    // `getValues` and `getFieldState` are plain functions created inside
+    // react-hook-form's `useForm` and are NOT wrapped in useCallback, so their
+    // reference changes on every render. Including them in the dependency array
+    // would re-run this effect on every render. They are intentionally omitted
+    // because the logic only needs to re-run when the form resets (new
+    // `defaultValues` identity) or when the field path / kind changes.
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [defaultValues, field.path, field.isRuntimeExpression]);
 

packages/open-workflow-diagram-editor/src/side-panel/forms/customFields/StructuredValueField.tsx

@@ -19,6 +19,7 @@ import { Controller, useFormContext, useFormState } from "react-hook-form";
 import { dump, load } from "js-yaml";
 import { Textarea } from "../ui/textarea";
 import type { JsonField } from "../../../core/schemaToFormFields";
+import type { ContentFormat } from "../../../core/workflowSdk";
 import { useTaskFormContext, getNestedValue } from "../taskFormContext";
 import { useFieldError, FieldWithError } from "./fieldHelpers";
 
@@ -31,7 +32,7 @@ export type StructuredValueFieldProps = {
   id?: string | undefined;
 };
 
-function valueToText(value: unknown, format: "json" | "yaml"): string {
+function valueToText(value: unknown, format: ContentFormat): string {
   if (value === undefined || value === null) return "";
   if (typeof value === "string") return value;
   try {
@@ -43,7 +44,7 @@ function valueToText(value: unknown, format: "json" | "yaml"): string {
   }
 }
 
-function parseText(text: string, format: "json" | "yaml"): unknown {
+function parseText(text: string, format: ContentFormat): unknown {
   if (format === "json") {
     return JSON.parse(text);
   }
@@ -104,6 +105,12 @@ export function StructuredValueField({ field, id }: StructuredValueFieldProps) {
       return;
     }
     setText(valueToText(fromDefault, field.format));
+    // The effect intentionally reads `prevDefaultValuesRef`, `prevFormatRef`,
+    // and `prevPathRef` as mutable ref containers — refs are stable objects and
+    // must NOT be in the dependency array (they never change identity, so adding
+    // them would not trigger the effect; and their `.current` mutations are the
+    // side-effect, not the trigger). The deps are exactly the reactive values
+    // that should re-run the effect: `defaultValues`, `field.format`, `field.path`.
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [defaultValues, field.format, field.path]);