Update build process to allow for future additional entrypoints

scripts/rollup.config.mjs

@@ -1,3 +1,5 @@
+import fs from 'node:fs/promises';
+import path from 'node:path/posix';
 import { readFileSync } from 'node:fs';
 
 import * as prettier from 'prettier';
@@ -8,6 +10,61 @@ import terser from '@rollup/plugin-terser';
 import cjsCheck from 'rollup-plugin-cjs-check';
 import dts from 'rollup-plugin-dts';
 
+const normalize = name => []
+  .concat(name)
+  .join(' ')
+  .replace(/[@\s/.]+/g, ' ')
+  .trim()
+  .replace(/\s+/, '-')
+  .toLowerCase();
+
+const extension = name => {
+  if (/\.d.ts$/.test(name)) {
+    return '.d.ts';
+  } else {
+    return path.extname(name);
+  }
+};
+
+const meta = JSON.parse(readFileSync('package.json'));
+const name = normalize(meta.name);
+
+const externalModules = [
+  ...Object.keys(meta.dependencies || {}),
+  ...Object.keys(meta.peerDependencies || {}),
+];
+
+const external = new RegExp(`^(${externalModules.join('|')})($|/)`);
+
+const exports = {};
+for (const key in meta.exports) {
+  const entry = meta.exports[key];
+  if (typeof entry === 'object' && !!entry.source) {
+    const entryPath = normalize(key);
+    const entryName = normalize([name, entryPath]);
+    exports[entryName] = {
+      path: entryPath,
+      ...entry,
+    };
+  }
+}
+
+const commonConfig = {
+  input: Object.entries(exports).reduce((input, [exportName, entry]) => {
+    input[exportName] = entry.source;
+    return input;
+  }, {}),
+  onwarn: () => {},
+  external(id) {
+    return external.test(id);
+  },
+  treeshake: {
+    unknownGlobalSideEffects: false,
+    tryCatchDeoptimization: false,
+    moduleSideEffects: false,
+  },
+};
+
 const commonPlugins = [
   resolve({
     extensions: ['.mjs', '.js', '.ts'],
@@ -22,154 +79,176 @@ const commonPlugins = [
   }),
 ];
 
-const packageJson = JSON.parse(readFileSync('package.json'));
-const externalModules = Object.keys(packageJson.dependencies);
-const externalPredicate = new RegExp(`^(${externalModules.join('|')})($|/)`);
-const external = (id) => externalPredicate.test(id);
+const commonOutput = {
+  dir: './',
+  exports: 'auto',
+  sourcemap: true,
+  sourcemapExcludeSources: false,
+  hoistTransitiveImports: false,
+  indent: false,
+  freeze: false,
+  strict: false,
+  generatedCode: {
+    preset: 'es5',
+    reservedNamesAsProps: false,
+    objectShorthand: false,
+    constBindings: false,
+  },
+};
 
-const jsPlugins = [
-  ...commonPlugins,
+const outputPlugins = [
+  {
+    name: 'outputPackageJsons',
+    async writeBundle() {
+      for (const key in exports) {
+        const entry = exports[key];
+        if (entry.path) {
+          const output = path.relative(entry.path, process.cwd());
+          const json = JSON.stringify({
+            name: key,
+            private: true,
+            version: '0.0.0',
+            main: path.join(output, entry.require),
+            module: path.join(output, entry.import),
+            types: path.join(output, entry.types),
+            source: path.join(output, entry.source),
+            exports: {
+              '.': {
+                types: path.join(output, entry.types),
+                import: path.join(output, entry.import),
+                require: path.join(output, entry.require),
+                source: path.join(output, entry.source),
+              },
+            },
+          }, null, 2);
 
-  babel({
-    babelrc: false,
-    babelHelpers: 'bundled',
-    extensions: ['mjs', 'js', 'jsx', 'ts', 'tsx'],
-    exclude: 'node_modules/**',
-    presets: [],
-    plugins: [
-      '@babel/plugin-transform-typescript',
-      '@babel/plugin-transform-block-scoping',
-    ],
-  }),
-];
+          await fs.mkdir(entry.path, { recursive: true });
+          await fs.writeFile(path.join(entry.path, 'package.json'), json);
+        }
+      }
+    },
+  },
+
+  cjsCheck(),
 
-const dtsPlugins = [
-  ...commonPlugins,
-  dts(),
+  terser({
+    warnings: true,
+    ecma: 2015,
+    keep_fnames: true,
+    ie8: false,
+    compress: {
+      pure_getters: true,
+      toplevel: true,
+      booleans_as_integers: false,
+      keep_fnames: true,
+      keep_fargs: true,
+      if_return: false,
+      ie8: false,
+      sequences: false,
+      loops: false,
+      conditionals: false,
+      join_vars: false,
+    },
+    mangle: {
+      module: true,
+      keep_fnames: true,
+    },
+    output: {
+      beautify: true,
+      braces: true,
+      indent_level: 2,
+    },
+  }),
 ];
 
-const output = format => {
-  const extension = format === 'esm' ? '.mjs' : '.js';
-  return {
-    chunkFileNames: '[hash]' + extension,
-    entryFileNames: '[name]' + extension,
-    dir: './dist',
-    exports: 'named',
-    sourcemap: true,
-    sourcemapExcludeSources: false,
-    indent: false,
-    freeze: false,
-    strict: false,
-    format,
-    // NOTE: All below settings are important for cjs-module-lexer to detect the export
-    // When this changes (and terser mangles the output) this will interfere with Node.js ESM intercompatibility
-    esModule: format !== 'esm',
-    externalLiveBindings: format !== 'esm',
+export default [
+  {
+    ...commonConfig,
     plugins: [
-      cjsCheck(),
-
-      terser({
-        warnings: true,
-        ecma: 2015,
-        keep_fnames: true,
-        ie8: false,
-        compress: {
-          pure_getters: true,
-          toplevel: true,
-          booleans_as_integers: false,
-          keep_fnames: true,
-          keep_fargs: true,
-          if_return: false,
-          ie8: false,
-          sequences: false,
-          loops: false,
-          conditionals: false,
-          join_vars: false,
+      ...commonPlugins,
+      babel({
+        babelrc: false,
+        babelHelpers: 'bundled',
+        extensions: ['mjs', 'js', 'jsx', 'ts', 'tsx'],
+        exclude: 'node_modules/**',
+        presets: [],
+        plugins: [
+          '@babel/plugin-transform-typescript',
+          '@babel/plugin-transform-block-scoping',
+        ],
+      }),
+    ],
+    output: [
+      {
+        ...commonOutput,
+        format: 'esm',
+        chunkFileNames(chunk) {
+          return `dist/chunks/[name]-chunk${extension(chunk.name) || '.mjs'}`;
+        },
+        entryFileNames(chunk) {
+          return chunk.isEntry
+            ? path.normalize(exports[chunk.name].import)
+            : `dist/[name].mjs`;
         },
-        mangle: {
-          module: true,
-          keep_fnames: true,
+        plugins: outputPlugins,
+      },
+      {
+        ...commonOutput,
+        format: 'cjs',
+        esModule: true,
+        externalLiveBindings: true,
+        chunkFileNames(chunk) {
+          return `dist/chunks/[name]-chunk${extension(chunk.name) || '.js'}`;
         },
-        output: {
-          beautify: true,
-          braces: true,
-          indent_level: 2,
+        entryFileNames(chunk) {
+          return chunk.isEntry
+            ? path.normalize(exports[chunk.name].require)
+            : `dist/[name].js`;
         },
-      }),
+        plugins: outputPlugins,
+      },
     ],
-    generatedCode: {
-      preset: 'es5',
-      reservedNamesAsProps: false,
-      objectShorthand: false,
-      constBindings: false,
-    },
-  };
-};
-
-const commonConfig = {
-  input: {
-    'gql-tada': './src/index.ts',
-  },
-  onwarn: () => {},
-  external,
-  treeshake: {
-    unknownGlobalSideEffects: false,
-    tryCatchDeoptimization: false,
-    moduleSideEffects: false,
   },
-};
-
-const jsConfig = {
-  ...commonConfig,
-  plugins: jsPlugins,
-  output: [
-    output('esm'),
-    output('cjs'),
-  ],
-};
 
-const dtsConfig = {
-  ...commonConfig,
-  input: {
-    'gql-tada': './src/index.ts',
-  },
-  onwarn: () => {},
-  external,
-  plugins: dtsPlugins,
-  treeshake: {
-    unknownGlobalSideEffects: false,
-    tryCatchDeoptimization: false,
-    moduleSideEffects: false,
-  },
-  output: {
-    dir: './dist',
-    entryFileNames: '[name].d.ts',
-    format: 'es',
+  {
+    ...commonConfig,
     plugins: [
-      {
-        renderChunk(code, chunk) {
-          if (chunk.fileName.endsWith('d.ts')) {
-            const gqlImportRe = /(import\s+(?:[*\s{}\w\d]+)\s*from\s*'graphql';?)/g;
-            code = code.replace(gqlImportRe, x => '/*!@ts-ignore*/\n' + x);
-
-            code = prettier.format(code, {
-              filepath: chunk.fileName,
-              parser: 'typescript',
-              singleQuote: true,
-              tabWidth: 2,
-              printWidth: 100,
-              trailingComma: 'es5',
-            });
-
-            return code;
-          }
-        },
-      },
+      ...commonPlugins,
+      dts(),
     ],
-  },
-};
+    output: {
+      ...commonOutput,
+      sourcemap: false,
+      format: 'dts',
+      chunkFileNames(chunk) {
+        return `dist/chunks/[name]-chunk${extension(chunk.name) || '.d.ts'}`;
+      },
+      entryFileNames(chunk) {
+        return chunk.isEntry
+          ? path.normalize(exports[chunk.name].types)
+          : `dist/[name].d.ts`;
+      },
+      plugins: [
+        {
+          renderChunk(code, chunk) {
+            if (chunk.fileName.endsWith('d.ts')) {
+              const gqlImportRe = /(import\s+(?:[*\s{}\w\d]+)\s*from\s*'graphql';?)/g;
+              code = code.replace(gqlImportRe, x => '/*!@ts-ignore*/\n' + x);
 
-export default [
-  jsConfig,
-  dtsConfig,
+              code = prettier.format(code, {
+                filepath: chunk.fileName,
+                parser: 'typescript',
+                singleQuote: true,
+                tabWidth: 2,
+                printWidth: 100,
+                trailingComma: 'es5',
+              });
+
+              return code;
+            }
+          },
+        },
+      ],
+    },
+  },
 ];