feat(core): added factoryMethods

Author: mironbalcerzak

docs/content/docs/reference/configuration/output.mdx

@@ -1677,6 +1677,72 @@ export interface Pet {
 }
 ```
 
+## factoryMethods
+
+**Type:** `Object`
+**Default:** `{ generate: false }`
+
+Generate factory methods for DTOs (Data Transfer Objects) initialized with safe default values. Useful for testing and initializing empty state.
+Functionality handles OpenAPI `readOnly` and `writeOnly` flags to generate appropriate payload structures:
+- **Required properties:** Always included in the factory output, regardless of their visibility flags.
+- **Optional `readOnly` properties:** Always omitted from the factory output, as they would be dropped by the server.
+- **Optional `writeOnly` properties:** Always included in the factory output (even if `optionalPropertyStrategy` is set to `'omit'`).
+
+```ts title="orval.config.ts"
+export default defineConfig({
+  petstore: {
+    output: {
+      factoryMethods: {
+        generate: true,
+        functionNamePrefix: 'create',
+        mode: 'separate-file',
+        optionalPropertyStrategy: 'include',
+        outputDirectory: `#output.workspace.schemas`,
+      },
+    },
+  },
+});
+```
+
+### generate
+
+**Type:** `Boolean`
+**Default:** `false`
+
+Enables or disables factory generation.
+
+### functionNamePrefix
+
+**Type:** `String`
+**Default:** `'create'`
+
+Prefix for the generated factory function names.
+
+### mode
+
+**Type:** `'inline-with-schema' | 'separate-file' | 'combined-separate-file'`
+**Default:** `'separate-file'`
+
+Where to generate the factory methods:
+- `inline-with-schema`: Appends the factory function to the schema file.
+- `separate-file`: Creates a `{schema}.factory.ts` with factory method. By default it is placed next to schema file.
+- `combined-separate-file`: Aggregates all factory methods into a single `factoryMethods.ts` file.
+
+### optionalPropertyStrategy
+
+**Type:** `'include' | 'omit'`
+**Default:** `'include'`
+
+Determines whether optional schema properties are included in the default factory output.
+
+### outputDirectory
+
+**Type:** `String`
+**Default:** `#output.workspace.schemas`
+
+Defaults to the value configured in `#output.workspace.schemas`.
+Determines where factory methods will be generated (can be used to generated methods away from schema directory).
+Takes effect only when used `mode` is `separate-file` or `combined-separate-file`.
 ---
 
 ## Other Options

packages/angular/src/http-client.test.ts

@@ -125,6 +125,13 @@ const createOutput = (
     optionsParamRequired: false,
     unionAddMissingProperties: false,
     propertySortOrder: 'Specification',
+    factoryMethods: {
+      generate: false,
+      functionNamePrefix: 'create',
+      mode: 'inline-with-schema',
+      outputDirectory: '',
+      optionalPropertyStrategy: 'omit',
+    },
     ...overrides,
   } satisfies NormalizedOutputOptions;
 

packages/angular/src/http-resource.test.ts

@@ -135,6 +135,13 @@ const createOutput = (
     optionsParamRequired: false,
     unionAddMissingProperties: false,
     propertySortOrder: 'Specification',
+    factoryMethods: {
+      generate: false,
+      functionNamePrefix: 'create',
+      mode: 'inline-with-schema',
+      outputDirectory: '',
+      optionalPropertyStrategy: 'omit',
+    },
     ...overrides,
   } satisfies NormalizedOutputOptions;