Support for local env values or multiple paths

[danilofuchs]

create-react-app has an awesome environment variables resolution pattern:
https://create-react-app.dev/docs/adding-custom-environment-variables/#what-other-env-files-can-be-used
It allows for users to define .env.development (tracked by git) and .env.development.local (not committed to the repo), .env which works on all envs, etc.

Another issue proposed to allow multiple paths, but in another context: #29.

This way, you could perhaps configure the plugin like this (given path supports variables: #52):

custom:
  dotenv:
    path: 
        - .env
        - .env.${self:stage}
        - .env.${self:stage}.local

The plugin would load each path sequentially, overriding envs as it goes.

Alternatively, the plugin would do these resolutions automatically.

This is the implementation on create-react-app. It takes into account several framework-specific things, but the main part, which applies here, is this: https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/config/env.js#L26-L49

EDIT

Apparently, this behaviour was taken from Rails:
https://github.com/bkeepers/dotenv#what-other-env-files-can-i-use

I made the change on a fork of mine

[danilofuchs]

My approach looks something like this:

    /**
     * @param {string} env
     * @returns {string[]}
     */
    resolveEnvFileNames(env) {
        if (this.config && this.config.path) {
            return this.config.path;
        }

        // https://github.com/bkeepers/dotenv#what-other-env-files-can-i-use
        const dotenvFiles = [
            `.env.${env}.local`,
            `.env.${env}`,
            // Don't include `.env.local` for `test` environment
            // since normally you expect tests to produce the same
            // results for everyone
            env !== "test" && `.env.local`,
            `.env`,
        ];

        const basePath =
            this.config && this.config.basePath ? this.config.basePath : "";

        const filesNames = dotenvFiles.map((file) => basePath + file);

        return filesNames.filter((fileName) => fs.existsSync(fileName));
    }

    /**
     * @param {string} env
     */
    loadEnv(env) {
        const envFileNames = this.resolveEnvFileNames(env);
        try {
            const envVarsArray = envFileNames.map(
                (fileName) =>
                    dotenvExpand(dotenv.config({ path: fileName })).parsed
            );

            const envVars = envVarsArray.reduce(
                (acc, curr) => ({ ...acc, ...curr }),
                {}
            );

           // Rest of code
           // ...

[dekked]

This is great @danilofuchs! Can you link to your fork?

[danilofuchs]

I actually cloned the repository directly into my project. I will open a proper fork of your repository so you can take a look.

I didn't implement the option to define the paths in the config