Export type instead of interface (optionaly) (#868)

* prepare tests that test flag --export-type that should tell the app to export types instead of interfaces

* implement optional exporting type instead of interface

* add --export-type flag into cli that is passed as option into the transformer

Author: dominikdosoudil

bin/cli.js

@@ -25,6 +25,7 @@ Options
   --default-non-nullable       (optional) If a schema object has a default value set, don’t mark it as nullable
   --prettier-config, -c        (optional) specify path to Prettier config file
   --raw-schema                 (optional) Parse as partial schema (raw components)
+  --export-type                (optional) Export type instead of interface
   --version                    (optional) Force schema parsing version
 `;
 
@@ -41,7 +42,7 @@ function errorAndExit(errorMessage) {
 const [, , input, ...args] = process.argv;
 const flags = parser(args, {
   array: ["header"],
-  boolean: ["defaultNonNullable", "immutableTypes", "rawSchema"],
+  boolean: ["defaultNonNullable", "immutableTypes", "rawSchema", "exportType"],
   number: ["version"],
   string: ["auth", "header", "headersObject", "httpMethod", "prettierConfig"],
   alias: {
@@ -90,6 +91,7 @@ async function generateSchema(pathToSpec) {
     version: flags.version,
     httpHeaders,
     httpMethod: flags.httpMethod,
+    exportType: flags.exportType,
   });
 
   // output

src/index.ts

@@ -76,14 +76,17 @@ async function openapiTS(
   // 2a. root schema
   if (!options?.version && !ctx.rawSchema) ctx.version = swaggerVersion(rootSchema as any); // note: root version cascades down to all subschemas
   const rootTypes = transformAll(rootSchema, { ...ctx });
+  const exportedKind = options.exportType === true ? "type" : "interface";
+  const exportedKindOperator = options.exportType === true ? " =" : "";
+  const exportedKindSemicolon = options.exportType === true ? ";" : "";
   for (const k of Object.keys(rootTypes)) {
     if (typeof rootTypes[k] === "string") {
-      output += `export interface ${k} {\n  ${rootTypes[k]}\n}\n\n`;
+      output += `export ${exportedKind} ${k}${exportedKindOperator} {\n  ${rootTypes[k]}\n}\n\n`;
     }
   }
 
   // 2b. external schemas (subschemas)
-  output += `export interface external {\n`;
+  output += `export ${exportedKind} external${exportedKindOperator} {\n`;
   const externalKeys = Object.keys(external);
   externalKeys.sort((a, b) => a.localeCompare(b, "en", { numeric: true })); // sort external keys because they may have resolved in a different order each time
   for (const subschemaURL of externalKeys) {
@@ -94,7 +97,7 @@ async function openapiTS(
     }
     output += `  }\n`;
   }
-  output += `}\n\n`;
+  output += `}${exportedKindSemicolon}\n\n`;
 
   // 3. Prettify
   let prettierOptions: prettier.Options = {

src/types.ts

@@ -151,6 +151,10 @@ export interface SwaggerToTSOptions {
    * @default {string} GET
    */
   httpMethod?: string;
+  /**
+   * (optional) Export type instead of interface
+   */
+  exportType?: boolean;
 }
 
 /** Context passed to all submodules */

test/v3/expected/consts-enums.exported-type.ts

@@ -0,0 +1,35 @@
+/**
+ * This file was auto-generated by openapi-typescript.
+ * Do not make direct changes to the file.
+ */
+
+export type paths = {
+  "/test": {
+    get: {
+      responses: {
+        /** A list of types. */
+        200: unknown;
+      };
+    };
+  };
+};
+
+export type components = {
+  schemas: {
+    /** @description Enum with null and nullable */
+    MyType: {
+      /** @enum {string|null} */
+      myEnumTestFieldNullable?: ("foo" | "bar" | null) | null;
+      /** @enum {string|null} */
+      myEnumTestField?: ("foo" | "bar" | null) | null;
+      /** @constant */
+      myConstTestField?: "constant-value";
+      /** @constant */
+      myConstTestFieldNullable?: 4 | null;
+    };
+  };
+};
+
+export type operations = {};
+
+export type external = {};

test/v3/expected/github.exported-type.ts

@@ -0,0 +1,150 @@
+/**
+ * This file was auto-generated by openapi-typescript.
+ * Do not make direct changes to the file.
+ */
+
+export type paths = {
+  "/contacts": {
+    get: operations["getContacts"];
+  };
+  "/contacts/{userUid}": {
+    get: operations["getContactInfo"];
+  };
+  "/contacts/{userUid}/icon": {
+    get: operations["getContactIcon"];
+  };
+  "/contacts/me": {
+    get: operations["getMyInfo"];
+  };
+  "/contacts/me/icon": {
+    get: operations["getMyIcon"];
+    delete: operations["deleteMyIcon"];
+  };
+};
+
+export type components = {
+  schemas: {
+    /** Parent of most important objects */
+    BaseEntity: {
+      /**
+       * Format: nanoid
+       * @deprecated
+       * @description Test description with deprecated
+       * @example njbusD52k6YoRG346tPgD
+       */
+      uid?: string;
+      /**
+       * Format: date-time
+       * @description It's date example
+       * @example 1999-03-31 15:00:00.000
+       */
+      created_at?: string;
+      /**
+       * Format: date-time
+       * @example 2020-07-10 10:10:00.000
+       */
+      updated_at?: string;
+      deleted?: boolean;
+    };
+    /** Image for preview */
+    Image: {
+      /** @example https://shantichat.com/data/V1StGXR8_Z5jdHi6B-myT/white-rabbit.png */
+      url: string;
+      /** @example 128 */
+      width: unknown;
+      /** @example 128 */
+      height: unknown;
+      /** @example LEHV6nWB2yk8pyo0adR*.7kCMdnj */
+      blurhash?: string;
+    };
+    /** User object */
+    User: components["schemas"]["BaseEntity"] & {
+      /** @example Thomas A. Anderson */
+      name?: string;
+      /**
+       * @default test
+       * @example The One
+       */
+      description?: string;
+      icon?: components["schemas"]["Image"];
+      /** @example America/Chicago */
+      timezone?: string;
+      /**
+       * Format: date-time
+       * @example 2020-07-10 15:00:00.000
+       */
+      last_online_at?: string;
+    };
+  };
+};
+
+export type operations = {
+  getContacts: {
+    responses: {
+      /** OK */
+      200: {
+        content: {
+          "application/json": components["schemas"]["User"][];
+        };
+      };
+    };
+  };
+  getContactInfo: {
+    parameters: {
+      path: {
+        userUid: string;
+      };
+    };
+    responses: {
+      /** OK */
+      200: {
+        content: {
+          "application/json": components["schemas"]["User"];
+        };
+      };
+    };
+  };
+  getContactIcon: {
+    parameters: {
+      path: {
+        userUid: string;
+      };
+    };
+    responses: {
+      /** OK */
+      200: {
+        content: {
+          "application/json": components["schemas"]["Image"];
+        };
+      };
+    };
+  };
+  getMyInfo: {
+    responses: {
+      /** OK */
+      200: {
+        content: {
+          "application/json": components["schemas"]["User"];
+        };
+      };
+    };
+  };
+  getMyIcon: {
+    responses: {
+      /** OK */
+      200: {
+        content: {
+          "application/json": components["schemas"]["Image"];
+        };
+      };
+    };
+  };
+  deleteMyIcon: {
+    responses: {
+      /** OK */
+      200: unknown;
+    };
+  };
+};
+
+export type external = {};