feat: Support for Additional Language Modules (Experimental)

[johnsoncodehk]

Add vueCompilerOptions.experimentalAdditionalLanguageModules option to support config additional LangaugeModule, it can be used to generate virtual files for arbitrary source files other than .vue, or to add global virtual files.

Note that this option is only affect for *.ts when the TypeScript Plugin or Takeover mode is enabled, but always affect for *.vue.

And Show Virtual Files command only works for generated virtual files from source files, for global virtual files you can only debug with Write Virtual Files command for now.

Example

• tsconfig.json:

{
  "vueCompilerOptions": {
    "experimentalAdditionalLanguageModules": ["./nuxt-virtual-files.js"]
  }
}

• nuxt-virtual-files.js:

/**
 * @type {import('@volar/language-core').LanguageModule}
 */
module.exports = {
    createFile() {
        return;
    },
    updateFile() {
        return;
    },
    proxyLanguageServiceHost(host) {

        const ts = host.getTypeScriptModule();
        const nitroScript = {
            projectVersion: '',
            fileName: host.getCurrentDirectory() + '/.nuxt/types/nitro.d.ts',
            _version: 0,
            _snapshot: ts.ScriptSnapshot.fromString(''),
            get version() {
                this.update();
                return this._version;
            },
            get snapshot() {
                this.update();
                return this._snapshot;
            },
            update() {
                if (!host.getProjectVersion || host.getProjectVersion() !== this.projectVersion) {
                    this.projectVersion = host.getProjectVersion?.() ?? '';
                    const newText = this.generateText();
                    if (newText !== this._snapshot.getText(0, this._snapshot.getLength())) {
                        console.log(newText);
                        this._version++;
                        this._snapshot = ts.ScriptSnapshot.fromString(newText);
                    }
                }
            },
            generateText() {
                const projectFileNames = host.getScriptFileNames().map(fileName => fileName.replace(host.getCurrentDirectory(), ''));
                const apiFiles = projectFileNames.filter(fileName => fileName.startsWith('/server/api') && fileName.endsWith('.ts'));
                const apiFileBasePaths = apiFiles.map(fileName => fileName.slice('/server/'.length, -'.ts'.length));
                return `
                    // Generated by nitro
                    declare module '@nuxt/nitro' {
                        type Awaited<T> = T extends PromiseLike<infer U> ? Awaited<U> : T
                        interface InternalApi {
                            ${apiFileBasePaths.map(name => `'/${name}': Awaited<ReturnType<typeof import("../../server/${name}").default>>`).join(('\n'))}
                        }
                    }
                    export {}
                `;
            },
        };

        return {
            getScriptFileNames() {
                return [
                    ...host.getScriptFileNames(),
                    nitroScript.fileName,
                ];
            },
            getScriptVersion(fileName) {
                if (fileName === nitroScript.fileName) {
                    return nitroScript.version;
                }
                return host.getScriptVersion(fileName);
            },
            getScriptSnapshot(fileName) {
                if (fileName === nitroScript.fileName) {
                    return nitroScript.snapshot;
                }
                return host.getScriptSnapshot(fileName);
            },
        }
    },
};