OpenAPI: Fix handling of primitive types in anyOf/allOf

.changeset/fresh-experts-lead.md

@@ -0,0 +1,5 @@
+---
+'fumadocs-openapi': patch
+---
+
+Fix handling of primitive types in `anyOf`/`allOf`

packages/openapi/src/playground/client.tsx

@@ -403,57 +403,64 @@ function SecurityTabs({
   return result;
 }
 
-const paramNames = ['Headers', 'Cookies', 'Query', 'Path'] as const;
-const paramTypes = ['header', 'cookie', 'query', 'path'] as const;
+const ParamTypes = ['path', 'header', 'cookie', 'query'] as const;
 
 function FormBody({
   parameters = [],
   fields = {},
   body,
 }: Pick<ClientProps, 'parameters' | 'body' | 'fields'>) {
-  const params = useMemo(() => {
-    return paramTypes.map((param) => parameters.filter((v) => v.in === param));
-  }, [parameters]);
+  const panels = useMemo(() => {
+    return ParamTypes.map((type) => {
+      const items = parameters.filter((v) => v.in === type);
+      if (items.length === 0) return;
+
+      return (
+        <CollapsiblePanel
+          key={type}
+          title={
+            {
+              header: 'Header',
+              cookie: 'Cookies',
+              query: 'Query',
+              path: 'Path',
+            }[type]
+          }
+        >
+          {items.map((field) => {
+            const fieldName = `${type}.${field.name}` as const;
+            const schema = (
+              field.content
+                ? field.content[Object.keys(field.content)[0]].schema
+                : field.schema
+            ) as ParsedSchema;
+
+            if (fields?.parameter) {
+              return renderCustomField(
+                fieldName,
+                schema,
+                fields.parameter,
+                field.name,
+              );
+            }
+
+            return (
+              <FieldSet
+                key={fieldName}
+                name={field.name}
+                fieldName={fieldName}
+                field={schema}
+              />
+            );
+          })}
+        </CollapsiblePanel>
+      );
+    });
+  }, [fields.parameter, parameters]);
 
   return (
     <>
-      {params.map((param, i) => {
-        if (param.length === 0) return;
-        const name = paramNames[i];
-        const type = paramTypes[i];
-
-        return (
-          <CollapsiblePanel key={name} title={name}>
-            {param.map((field) => {
-              const fieldName = `${type}.${field.name}` as const;
-              const schema = (
-                field.content
-                  ? field.content[Object.keys(field.content)[0]].schema
-                  : field.schema
-              ) as ParsedSchema;
-
-              if (fields?.parameter) {
-                return renderCustomField(
-                  fieldName,
-                  schema,
-                  fields.parameter,
-                  field.name,
-                );
-              }
-
-              return (
-                <FieldSet
-                  key={fieldName}
-                  name={field.name}
-                  fieldName={fieldName}
-                  field={schema}
-                />
-              );
-            })}
-          </CollapsiblePanel>
-        );
-      })}
-
+      {panels}
       {body && (
         <CollapsiblePanel title="Body">
           {fields.body ? (
@@ -474,48 +481,47 @@ function BodyInput({ field: _field }: { field: RequestSchema }) {
   if (field.format === 'binary')
     return <FieldSet field={field} fieldName="body" />;
 
+  if (isJson)
+    return (
+      <>
+        <button
+          className={cn(
+            buttonVariants({
+              color: 'secondary',
+              size: 'sm',
+              className: 'w-fit font-mono p-2',
+            }),
+          )}
+          onClick={() => setIsJson(false)}
+          type="button"
+        >
+          Close JSON Editor
+        </button>
+        <JsonInput fieldName="body" />
+      </>
+    );
+
   return (
-    <>
-      {isJson ? (
-        <>
-          <button
-            className={cn(
-              buttonVariants({
-                color: 'secondary',
-                size: 'sm',
-                className: 'w-fit font-mono p-2',
-              }),
-            )}
-            onClick={() => setIsJson(false)}
-            type="button"
-          >
-            Close JSON Editor
-          </button>
-          <JsonInput fieldName="body" />
-        </>
-      ) : (
-        <FieldSet
-          field={field}
-          fieldName="body"
-          collapsible={false}
-          name={
-            <button
-              className={cn(
-                buttonVariants({
-                  color: 'secondary',
-                  size: 'sm',
-                  className: 'p-2',
-                }),
-              )}
-              onClick={() => setIsJson(true)}
-              type="button"
-            >
-              Open JSON Editor
-            </button>
-          }
-        />
-      )}
-    </>
+    <FieldSet
+      field={field}
+      fieldName="body"
+      collapsible={false}
+      name={
+        <button
+          type="button"
+          className={cn(
+            buttonVariants({
+              color: 'secondary',
+              size: 'sm',
+              className: 'p-2',
+            }),
+          )}
+          onClick={() => setIsJson(true)}
+        >
+          Open JSON Editor
+        </button>
+      }
+    />
   );
 }
 

packages/openapi/src/playground/index.tsx

@@ -62,13 +62,7 @@ export async function APIPlayground({
     securities: parseSecurities(method, ctx),
     method: method.method,
     route: path,
-    parameters: method.parameters?.map(
-      (v) =>
-        ({
-          ...v,
-          schema: writeReferences((v.schema ?? true) as ParsedSchema, context),
-        }) as ParameterField,
-    ),
+    parameters: method.parameters as ParameterField[],
     body:
       bodyContent && mediaType
         ? ({

packages/openapi/src/playground/inputs.tsx

@@ -373,8 +373,9 @@ export function FieldSet({
 
   if (_field === false) return null;
 
-  if (field.oneOf) {
-    const showSelect = field.oneOf.length > 1;
+  if (info.unionField) {
+    const union = field[info.unionField]!;
+    const showSelect = union.length > 1;
 
     return (
       <FieldSet
@@ -382,7 +383,7 @@ export function FieldSet({
         name={name}
         fieldName={fieldName}
         isRequired={isRequired}
-        field={field.oneOf[info.oneOf]}
+        field={union[info.oneOf]}
         depth={depth + 1}
         slotType={showSelect ? false : slotType}
         toolbar={
@@ -397,7 +398,7 @@ export function FieldSet({
                   });
                 }}
               >
-                {field.oneOf.map((item, i) => (
+                {union.map((item, i) => (
                   <option key={i} value={i}>
                     {schemaToString(item)}
                   </option>

packages/openapi/src/playground/schema.tsx

@@ -4,6 +4,7 @@ import { createContext, ReactNode, useContext, useMemo, useState } from 'react';
 import { useFormContext } from 'react-hook-form';
 import { useEffectEvent } from 'fumadocs-core/utils/use-effect-event';
 import { getDefaultValue } from '@/playground/get-default-values';
+import type { ParsedSchema } from '@/utils/schema';
 
 interface SchemaContextType {
   references: Record<string, RequestSchema>;
@@ -11,9 +12,16 @@ interface SchemaContextType {
   ajv: Ajv2020;
 }
 
+type UnionField = 'anyOf' | 'allOf' | 'oneOf';
+
 export interface FieldInfo {
   selectedType?: string;
   oneOf: number;
+
+  /**
+   * The actual field that represents union members.
+   */
+  unionField?: UnionField;
 }
 
 const SchemaContext = createContext<SchemaContextType | undefined>(undefined);
@@ -67,67 +75,96 @@ export function useFieldInfo(
   updateInfo: (value: Partial<FieldInfo>) => void;
 } {
   const { fieldInfoMap, ajv } = useContext(SchemaContext)!;
-  const [_, trigger] = useState(0);
   const form = useFormContext();
   const keyName = `${fieldName}:${depth}`;
   const value = form.getValues(fieldName as 'body');
-  const info = fieldInfoMap.get(keyName) ?? {
-    oneOf: -1,
-  };
-
-  // update info if needed
-  if (!info.selectedType && Array.isArray(schema.type)) {
-    info.selectedType =
-      schema.type.find((type) =>
-        ajv.validate(
-          {
-            ...schema,
-            type,
-          },
-          value,
-        ),
-      ) ?? schema.type[0];
-  }
-
-  if (info.oneOf === -1 && schema.oneOf) {
-    info.oneOf = schema.oneOf.findIndex((item) => {
-      return ajv.validate(item, value);
-    });
-    if (info.oneOf === -1) info.oneOf = 0;
-  }
+  const [info, setInfo] = useState<FieldInfo>(() => {
+    return fieldInfoMap.get(keyName) ?? init();
+  });
 
   fieldInfoMap.set(keyName, info);
 
+  /**
+   * We automatically merge `allOf` | `anyOf` if all members are objects, but it's also possible for them to behave same as a union (`oneOf`).
+   */
+  function isUnion(anyOrAllOf: readonly ParsedSchema[]): boolean {
+    return anyOrAllOf.every((item) => {
+      if (typeof item === 'boolean') return true;
+
+      const u = item.anyOf || item.allOf;
+      return item.type !== 'object' && (!u || isUnion(u));
+    });
+  }
+
+  function getUnion(): [readonly ParsedSchema[], UnionField] | undefined {
+    if (schema.anyOf && isUnion(schema.anyOf)) {
+      return [schema.anyOf, 'anyOf'];
+    }
+
+    if (schema.allOf && isUnion(schema.allOf)) {
+      return [schema.allOf, 'allOf'];
+    }
+
+    if (schema.oneOf) return [schema.oneOf, 'oneOf'];
+  }
+
+  function init(): FieldInfo {
+    const union = getUnion();
+    if (union) {
+      const [members, field] = union;
+
+      let oneOf = members.findIndex((item) => ajv.validate(item, value));
+      if (oneOf === -1) oneOf = 0;
+
+      return {
+        oneOf,
+        unionField: field,
+      };
+    }
+
+    if (Array.isArray(schema.type)) {
+      const types = schema.type;
+
+      return {
+        selectedType:
+          types.find((type) => {
+            schema.type = type;
+            const match = ajv.validate(schema, value);
+            schema.type = types;
+
+            return match;
+          }) ?? types[0],
+        oneOf: -1,
+      };
+    }
+
+    return { oneOf: -1 };
+  }
+
   return {
     info,
     updateInfo: useEffectEvent((value) => {
-      const prev = fieldInfoMap.get(keyName);
-      if (!prev) return;
-
       const updated = {
-        ...prev,
+        ...info,
         ...value,
       };
 
       if (
-        updated.oneOf === prev.oneOf &&
-        updated.selectedType === prev.selectedType
+        updated.oneOf === info.oneOf &&
+        updated.selectedType === info.selectedType
       )
         return;
 
-      fieldInfoMap.set(keyName, updated);
-      form.setValue(
-        fieldName,
-        getDefaultValue(
-          schema.oneOf && updated.oneOf !== -1
-            ? schema.oneOf[updated.oneOf]
-            : {
-                ...schema,
-                type: value.selectedType ?? schema.type,
-              },
-        ),
-      );
-      trigger((prev) => prev + 1);
+      setInfo(updated);
+
+      let valueSchema: ParsedSchema = schema;
+      if (updated.unionField) {
+        valueSchema = schema[updated.unionField]![updated.oneOf];
+      } else if (updated.selectedType) {
+        valueSchema = { ...schema, type: updated.selectedType };
+      }
+
+      form.setValue(fieldName, getDefaultValue(valueSchema));
     }),
   };
 }

packages/openapi/src/utils/schema-to-string.ts

@@ -1,57 +1,62 @@
-import { type ParsedSchema, type ResolvedSchema } from '@/utils/schema';
+import { type ResolvedSchema } from '@/utils/schema';
 import type { ProcessedDocument } from '@/utils/process-document';
 
 export function schemaToString(
   value: ResolvedSchema,
   ctx?: ProcessedDocument,
 ): string {
-  function run(schema: ResolvedSchema, isRoot: boolean): string {
+  function union(union: readonly ResolvedSchema[], sep: string) {
+    const members = new Set();
+    let nullable = false;
+
+    for (const item of union) {
+      const result = run(item);
+      if (result === 'null') {
+        nullable = true;
+      } else if (result !== 'unknown') {
+        members.add(result);
+      }
+    }
+
+    const result = Array.from(members).join(sep);
+    return nullable ? `${result} | null` : result;
+  }
+
+  function run(schema: ResolvedSchema): string {
     if (schema === true) return 'any';
     else if (schema === false) return 'never';
 
-    if (isNullable(schema) && isRoot) {
-      const type = run(schema, false);
-
-      // null if schema only contains `nullable`
-      return type === 'unknown' ? 'null' : `${type} | null`;
-    }
-
     if (schema.title) return schema.title;
     const referenceName = ctx?.dereferenceMap.get(schema);
     if (referenceName) return referenceName.split('/').at(-1)!;
 
     if (Array.isArray(schema.type)) {
-      return schema.type
-        .map((type, _, originalType) => {
-          schema.type = type;
-          const str = run(schema, false);
-          schema.type = originalType;
+      const members = new Set();
+      const types = schema.type;
+      for (const type of types) {
+        schema.type = type;
+        const str = run(schema);
+        schema.type = types;
 
-          return str;
-        })
-        .filter((v) => v !== 'unknown' && v !== 'null')
-        .join(' | ');
+        if (str !== 'unknown') members.add(str);
+      }
+
+      return Array.from(members).join(' | ');
     }
 
     if (schema.type === 'array')
-      return `array<${schema.items ? run(schema.items, true) : 'unknown'}>`;
+      return `array<${schema.items ? run(schema.items) : 'unknown'}>`;
 
     if (schema.oneOf) {
-      return schema.oneOf
-        .map((one) => run(one, false))
-        .filter((v) => v !== 'unknown' && v !== 'null')
-        .join(' | ');
+      return union(schema.oneOf, ' | ');
     }
 
     const combinedOf = schema.anyOf ?? schema.allOf;
     if (combinedOf) {
-      return combinedOf
-        .map((one) => run(one, false))
-        .filter((v) => v !== 'unknown' && v !== 'null')
-        .join(' & ');
+      return union(combinedOf, ' & ');
     }
 
-    if (schema.not) return `not ${run(schema.not, false)}`;
+    if (schema.not) return `not ${run(schema.not)}`;
     if (schema.type === 'string' && schema.format === 'binary') return 'file';
 
     if (schema.type && Array.isArray(schema.type)) {
@@ -65,15 +70,5 @@ export function schemaToString(
     return 'unknown';
   }
 
-  return run(value, true);
-}
-
-function isNullable(schema: ParsedSchema): boolean {
-  if (typeof schema === 'boolean') return false;
-
-  if (Array.isArray(schema.type) && schema.type.includes('null')) return true;
-  const combined = schema.anyOf ?? schema.oneOf ?? schema.allOf;
-  if (combined && combined.some(isNullable)) return true;
-
-  return schema.type === 'null';
+  return run(value);
 }