bun.sh/test/bake/dev/dev-plugins.test.ts

// CSS tests concern bundling bugs with CSS files
import { devTest, minimalFramework, Step } from "../dev-server-harness";

// Note: more in depth testing of plugins is done in test/bundler/bundler_plugin.test.ts
devTest("onResolve", {
  framework: minimalFramework,
  pluginFile: `
    import * as path from 'path';
    export default [
      {
        name: 'a',
        setup(build) {
          build.onResolve({ filter: /trigger/ }, (args) => {
            return { path: path.join(import.meta.dirname, '/file.ts') };
          });
        },
      }
    ];
  `,
  files: {
    "file.ts": `
      export const value = 1;
    `,
    "routes/index.ts": `
      import { value } from 'trigger';

      export default function (req, meta) {
        return new Response('value: ' + value);
      }
    `,
  },
  async test(dev) {
    await dev.fetch("/").expect('value: 1');
  },
});
devTest("onLoad", {
  framework: minimalFramework,
  pluginFile: `
    import * as path from 'path';
    export default [
      {
        name: 'a',
        setup(build) {
          let a = 0;
          build.onLoad({ filter: /trigger/ }, (args) => {
            return { contents: 'export const value = 1;', loader: 'ts' };
          });
        },
      }
    ];
  `,
  files: {
    "trigger.ts": `
      throw new Error('should not be loaded');
    `,
    "routes/index.ts": `
      import { value } from '../trigger.ts';

      export default function (req, meta) {
        return new Response('value: ' + value);
      }
    `,
  },
  async test(dev) {
    await dev.fetch("/").expect('value: 1');
    await dev.fetch("/").expect('value: 1');
    await dev.fetch("/").expect('value: 1');
  },
});
// devTest("onLoad with watchFile", {
//   framework: minimalFramework,
//   pluginFile: `
//     import * as path from 'path';
//     export default [
//       {
//         name: 'a',
//         setup(build) {
//           let a = 0;
//           build.onLoad({ filter: /trigger/ }, (args) => {
//             a += 1;
//             return { contents: 'export const value = ' + a + ';', loader: 'ts' };
//           });
//         },
//       }
//     ];
//   `,
//   files: {
//     "trigger.ts": `
//       throw new Error('should not be loaded');
//     `,
//     "routes/index.ts": `
//       import { value } from '../trigger.ts';

//       export default function (req, meta) {
//         return new Response('value: ' + value);
//       }
//     `,
//   },
//   async test(dev) {
//     await dev.fetch("/").expect('value: 1');
//     await dev.fetch("/").expect('value: 1');
//     await dev.write("trigger.ts", "throw new Error('should not be loaded 2');");
//     await dev.fetch("/").expect('value: 2');
//     await dev.fetch("/").expect('value: 2');
//   },
// });