grammar-util.ts

/******************************************************************************
 * Copyright 2023 TypeFox GmbH
 * This program and the accompanying materials are made available under the
 * terms of the MIT License, which is available in the project root.
 ******************************************************************************/

import type { Module } from '../dependency-injection.js';
import type { LangiumGrammarServices } from '../grammar/langium-grammar-module.js';
import type { LanguageMetaData } from '../languages/language-meta-data.js';
import type { IParserConfig } from '../parser/parser-config.js';
import type { LangiumGeneratedServices, LangiumGeneratedSharedServices, LangiumCoreServices, LangiumSharedCoreServices, PartialLangiumCoreServices, PartialLangiumSharedCoreServices } from '../services.js';
import { createDefaultModule, createDefaultSharedModule } from '../default-module.js';
import { inject } from '../dependency-injection.js';
import { interpretAstReflection } from '../grammar/ast-reflection-interpreter.js';
import type * as ast from '../languages/generated/ast.js';
import { createLangiumGrammarServices } from '../grammar/langium-grammar-module.js';
import { getDocument } from '../utils/ast-util.js';
import { EmptyFileSystem } from '../workspace/file-system-provider.js';
import { URI } from '../utils/uri-util.js';
import { createLSPModule, createSharedLSPModule } from './langium-lsp-module.js';
import type { LangiumServices, PartialLangiumLSPServices, PartialLangiumSharedLSPServices } from './lsp-services.js';

/**
 * Create an instance of the language services for the given grammar (with LSP support). This function is very
 * useful when the grammar is defined on-the-fly, for example in tests of the Langium framework.
 */
export async function createServicesForGrammarWithLSP(config: {
    grammar: string | ast.Grammar,
    grammarServices?: LangiumGrammarServices,
    parserConfig?: IParserConfig,
    languageMetaData?: LanguageMetaData,
    module?: Module<LangiumServices, PartialLangiumCoreServices & PartialLangiumLSPServices>
    sharedModule?: Module<LangiumSharedCoreServices, PartialLangiumSharedCoreServices & PartialLangiumSharedLSPServices>
}): Promise<LangiumServices> {
    // TODO @montymxb: For the reviewer. This is a duplicate of 'createServicesForGrammar'
    // It would be nice to generalize this function to support both LSP and non-LSP services, but the solution here, so far, is a dupe.
    // Feel free to suggest a better solution (we should remove this pre-merge)
    const grammarServices = config.grammarServices ?? createLangiumGrammarServices(EmptyFileSystem).grammar;
    const uri = URI.parse('memory:///grammar.langium');
    const factory = grammarServices.shared.workspace.LangiumDocumentFactory;
    const grammarDocument = typeof config.grammar === 'string'
        ? factory.fromString(config.grammar, uri)
        : getDocument(config.grammar);
    const grammarNode = grammarDocument.parseResult.value as ast.Grammar;
    const documentBuilder = grammarServices.shared.workspace.DocumentBuilder;
    await documentBuilder.build([grammarDocument], { validation: false });

    const parserConfig = config.parserConfig ?? {
        skipValidations: false
    };
    const languageMetaData = config.languageMetaData ?? {
        caseInsensitive: false,
        fileExtensions: [`.${grammarNode.name?.toLowerCase() ?? 'unknown'}`],
        languageId: grammarNode.name ?? 'UNKNOWN'
    };
    const generatedSharedModule: Module<LangiumSharedCoreServices, LangiumGeneratedSharedServices> = {
        AstReflection: () => interpretAstReflection(grammarNode),
    };
    const generatedModule: Module<LangiumCoreServices, LangiumGeneratedServices> = {
        Grammar: () => grammarNode,
        LanguageMetaData: () => languageMetaData,
        parser: {
            ParserConfig: () => parserConfig
        }
    };
    const shared = inject(
        createDefaultSharedModule(EmptyFileSystem),
        createSharedLSPModule(EmptyFileSystem),
        generatedSharedModule,
        config.sharedModule
    );

    const services = inject(
        createDefaultModule({ shared }),
        createLSPModule({ shared }),
        generatedModule,
        config.module
    );

    shared.ServiceRegistry.register(services);
    return services;
}