serpapi-javascript is developed using Deno. Refer to https://deno.land/manual/getting_started/installation to install Deno.

Ensure you're running at least Deno v1.46.3.

deno --version
deno upgrade  # to upgrade to the latest version

Install the appropriate extension for your preferred editor/IDE: https://deno.land/manual/getting_started/setup_your_environment. The extension "integrates directly to the Deno CLI using the language server protocol. This helps ensure that the information you get about your code aligns to how that code will work when you try to run it under the Deno CLI."1

If you use VSCode, use the following settings (.vscode/settings.json):

{
  "deno.enablePaths": [
    "mod.ts",
    "version.ts",
    "src",
    "tests/*.ts",
    "tests/engines/",
    "scripts",
    "examples/deno"
  ],
  "deno.inlayHints.enumMemberValues.enabled": false,
  "deno.inlayHints.functionLikeReturnTypes.enabled": false,
  "deno.inlayHints.parameterNames.enabled": "none",
  "deno.inlayHints.parameterTypes.enabled": false,
  "deno.inlayHints.propertyDeclarationTypes.enabled": false,
  "deno.inlayHints.variableTypes.enabled": false,
  "[json]": {
    "editor.formatOnSave": true,
    "editor.defaultFormatter": "denoland.vscode-deno"
  },
  "[markdown]": {
    "editor.formatOnSave": true,
    "editor.defaultFormatter": "denoland.vscode-deno"
  },
  "[typescript]": {
    "editor.formatOnSave": true,
    "editor.defaultFormatter": "denoland.vscode-deno"
  }
}

Subsequently, install the vscode_deno extension and you're good to go.

• Every new feature must have associated tests.
• Tests are to be added in the tests/ folder.
• Use Deno's bdd.ts module to write tests. It provides the typical before and after hooks.

• When testing functionality that requires an API key, you need to ensure your API key is specified as an environment variable.
• Create a .env file with the following contents, replacing YOUR_API_KEY with your API key for the appropriate environment.

SERPAPI_TEST_KEY=YOUR_API_KEY

• Note that for tests that require an API key, the test suite skips them if an API key is not defined, e.g. the following test is ignored when no API key has been set in the .env file.

it("getJson with api key from config", {
  ignore: !HAS_API_KEY,
}, async () => {
  ...
});

deno task test         # Run tests
deno task test:watch   # Run tests and in watch mode: https://deno.land/manual/getting_started/command_line_interface#watch-mode
deno task test:cov     # Get test coverage by running tests

To run examples on your local source files, follow these steps.

1. Run deno task npm to build the files.
2. Update the respective example's package.json to depend on the local serpapi module instead,

   {
     "dependencies": {
       "dotenv": "*",
       "serpapi": "../../../npm"
     },
     "scripts": {
       "start": "node basic_example.js"
     }
   }

These test key functionality on different Node.js versions. They are ran on GitHub Actions, see the build workflow for more details.

To run these locally, follow these steps.

1. Run deno task npm to build the files.
2. Change directory to either the commonjs or esm folder.
3. Setup the intended Node.js version. For example, if you're using nvm, you can run nvm use 14 to run Node.js 14 for the current shell.
4. Run npm i, then npm test.

• Every exposed function must have associated JSDoc comments.
• documentation.js relies on these JSDoc comments to generate documentation in Markdown.
• Run the following to update README.md.

deno task docs:gen

TypeScript types are generated from the backend code. Follow these steps to update the types.

1. Run bundle exec rails libraries:generate_ts_types in the backend repository.
2. Replace everything in src/engines with the generated files from tmp/ts/engines.
3. Update mod.ts with the new engine exports from tmp/ts/mod.ts.

• Ensure all associated tests have been added
• Ensure all tests pass
• Ensure all relevant documentation have been updated
• Ensure the changelog has been updated with your changes

Once you've done the above, create a pull request with a clear description. SerpApi project members will then review the request.

1. Update changelog.
2. Merge the associated PR and ensure the "Build" workflow succeeds.
3. Update version.ts based on semantic versioning, e.g. 1.2.0.
4. Push version.ts. This triggers the "Release" workflow.
5. Verify that new versions have been released on npm and deno.land/x.

Footnotes

1. https://deno.land/manual/references/vscode_deno ↩