babel-plugin-adjust-imports.ts

import { emberVirtualPackages, emberVirtualPeerDeps, packageName as getPackageName } from '@embroider/shared-internals';
import { join, dirname, resolve } from 'path';
import type { NodePath } from '@babel/traverse';
import type * as Babel from '@babel/core';
import type { types as t } from '@babel/core';
import { PackageCache, Package, V2Package, explicitRelative } from '@embroider/shared-internals';
import { outputFileSync } from 'fs-extra';
import { Memoize } from 'typescript-memoize';
import { compile } from './js-handlebars';
import { handleImportDeclaration } from './mini-modules-polyfill';
import { ImportUtil } from 'babel-import-util';

interface State {
  adjustFile: AdjustFile;
  opts: Options | DeflatedOptions;
}

export interface DeflatedOptions {
  adjustImportsOptionsPath: string;
  relocatedFilesPath: string;
}

type BabelTypes = typeof t;

export interface Options {
  renamePackages: {
    [fromName: string]: string;
  };
  renameModules: {
    [fromName: string]: string;
  };
  extraImports: {
    absPath: string;
    target: string;
    runtimeName?: string;
  }[];
  externalsDir: string;
  activeAddons: {
    [packageName: string]: string;
  };
  relocatedFiles: { [relativePath: string]: string };
  resolvableExtensions: string[];
  emberNeedsModulesPolyfill: boolean;
}

const packageCache = PackageCache.shared('embroider-stage3');

type DefineExpressionPath = NodePath<t.CallExpression> & {
  node: t.CallExpression & {
    arguments: [t.StringLiteral, t.ArrayExpression, Function];
  };
};

export function isImportSyncExpression(t: BabelTypes, path: NodePath<any>) {
  if (
    !path ||
    !path.isCallExpression() ||
    path.node.callee.type !== 'Identifier' ||
    !path.get('callee').referencesImport('@embroider/macros', 'importSync')
  ) {
    return false;
  }

  const args = path.node.arguments;
  return Array.isArray(args) && args.length === 1 && t.isStringLiteral(args[0]);
}

export function isDynamicImportExpression(t: BabelTypes, path: NodePath<any>) {
  if (!path || !path.isCallExpression() || path.node.callee.type !== 'Import') {
    return false;
  }

  const args = path.node.arguments;
  return Array.isArray(args) && args.length === 1 && t.isStringLiteral(args[0]);
}

export function isDefineExpression(t: BabelTypes, path: NodePath<any>): path is DefineExpressionPath {
  // should we allow nested defines, or stop at the top level?
  if (!path.isCallExpression() || path.node.callee.type !== 'Identifier' || path.node.callee.name !== 'define') {
    return false;
  }

  const args = path.node.arguments;

  // only match define with 3 arguments define(name: string, deps: string[], cb: Function);
  return (
    Array.isArray(args) &&
    args.length === 3 &&
    t.isStringLiteral(args[0]) &&
    t.isArrayExpression(args[1]) &&
    t.isFunction(args[2])
  );
}

function adjustSpecifier(specifier: string, file: AdjustFile, opts: Options, isDynamic: boolean) {
  if (specifier === '@embroider/macros') {
    // the macros package is always handled directly within babel (not
    // necessarily as a real resolvable package), so we should not mess with it.
    // It might not get compiled away until *after* our plugin has run, which is
    // why we need to know about it.
    return specifier;
  }

  specifier = handleRenaming(specifier, file, opts);
  specifier = handleExternal(specifier, file, opts, isDynamic);
  return specifier;
}

function handleRenaming(specifier: string, sourceFile: AdjustFile, opts: Options) {
  let packageName = getPackageName(specifier);
  if (!packageName) {
    return specifier;
  }

  for (let [candidate, replacement] of Object.entries(opts.renameModules)) {
    if (candidate === specifier) {
      return replacement;
    }
    for (let extension of opts.resolvableExtensions) {
      if (candidate === specifier + '/index' + extension) {
        return replacement;
      }
      if (candidate === specifier + extension) {
        return replacement;
      }
    }
  }

  if (opts.renamePackages[packageName]) {
    return specifier.replace(packageName, opts.renamePackages[packageName]);
  }

  let pkg = sourceFile.owningPackage();
  if (!pkg || !pkg.isV2Ember()) {
    return specifier;
  }

  if (pkg.meta['auto-upgraded'] && pkg.name === packageName) {
    // we found a self-import, make it relative. Only auto-upgraded packages get
    // this help, v2 packages are natively supposed to use relative imports for
    // their own modules, and we want to push them all to do that correctly.
    let fullPath = specifier.replace(packageName, pkg.root);
    return explicitRelative(dirname(sourceFile.name), fullPath);
  }

  let relocatedIntoPkg = sourceFile.relocatedIntoPackage();
  if (relocatedIntoPkg && pkg.meta['auto-upgraded'] && relocatedIntoPkg.name === packageName) {
    // a file that was relocated into a package does a self-import of that
    // package's name. This can happen when an addon (like ember-cli-mirage)
    // emits files from its own treeForApp that contain imports of the app's own
    // fully qualified name.
    let fullPath = specifier.replace(packageName, relocatedIntoPkg.root);
    return explicitRelative(dirname(sourceFile.name), fullPath);
  }

  return specifier;
}

function isExplicitlyExternal(specifier: string, fromPkg: V2Package): boolean {
  return Boolean(fromPkg.isV2Addon() && fromPkg.meta['externals'] && fromPkg.meta['externals'].includes(specifier));
}

function isResolvable(packageName: string, fromPkg: Package): false | Package {
  try {
    let dep = packageCache.resolve(packageName, fromPkg);
    if (!dep.isEmberPackage() && !fromPkg.hasDependency('ember-auto-import')) {
      return false;
    }
    return dep;
  } catch (err) {
    if (err.code !== 'MODULE_NOT_FOUND') {
      throw err;
    }
    return false;
  }
}

const dynamicMissingModule = compile(`
  throw new Error('Could not find module \`{{{js-string-escape moduleName}}}\`');
`) as (params: { moduleName: string }) => string;

const externalTemplate = compile(`
{{#if (eq runtimeName "require")}}
const m = window.requirejs;
{{else}}
const m = window.require("{{{js-string-escape runtimeName}}}");
{{/if}}
{{!-
  There are plenty of hand-written AMD defines floating around
  that lack this, and they will break when other build systems
  encounter them.

  As far as I can tell, Ember's loader was already treating this
  case as a module, so in theory we aren't breaking anything by
  marking it as such when other packagers come looking.

  todo: get review on this part.
-}}
if (m.default && !m.__esModule) {
  m.__esModule = true;
}
module.exports = m;
`) as (params: { runtimeName: string }) => string;

function handleExternal(specifier: string, sourceFile: AdjustFile, opts: Options, isDynamic: boolean): string {
  let pkg = sourceFile.owningPackage();
  if (!pkg || !pkg.isV2Ember()) {
    return specifier;
  }

  let packageName = getPackageName(specifier);
  if (!packageName) {
    // This is a relative import. We don't automatically externalize those
    // because it's rare, and by keeping them static we give better errors. But
    // we do allow them to be explicitly externalized by the package author (or
    // a compat adapter). In the metadata, they would be listed in
    // package-relative form, so we need to convert this specifier to that.
    let absoluteSpecifier = resolve(dirname(sourceFile.name), specifier);
    let packageRelativeSpecifier = explicitRelative(pkg.root, absoluteSpecifier);
    if (isExplicitlyExternal(packageRelativeSpecifier, pkg)) {
      let publicSpecifier = absoluteSpecifier.replace(pkg.root, pkg.name);
      return makeExternal(publicSpecifier, sourceFile, opts);
    } else {
      return specifier;
    }
  }

  // absolute package imports can also be explicitly external based on their
  // full specifier name
  if (isExplicitlyExternal(specifier, pkg)) {
    return makeExternal(specifier, sourceFile, opts);
  }

  if (!pkg.meta['auto-upgraded'] && emberVirtualPeerDeps.has(packageName)) {
    // Native v2 addons are allowed to use the emberVirtualPeerDeps like
    // `@glimmer/component`. And like all v2 addons, it's important that they
    // see those dependencies after those dependencies have been converted to
    // v2.
    //
    // But unlike auto-upgraded addons, native v2 addons are not necessarily
    // copied out of their original place in node_modules. And from that
    // original place they might accidentally resolve the emberVirtualPeerDeps
    // that are present there in v1 format.
    //
    // So before we even check isResolvable, we adjust these imports to point at
    // the app's copies instead.
    if (emberVirtualPeerDeps.has(packageName)) {
      if (!opts.activeAddons[packageName]) {
        throw new Error(`${pkg.name} is trying to import the app's ${packageName} package, but it seems to be missing`);
      }
      return explicitRelative(dirname(sourceFile.name), specifier.replace(packageName, opts.activeAddons[packageName]));
    }
  }

  let relocatedPkg = sourceFile.relocatedIntoPackage();
  if (relocatedPkg) {
    // this file has been moved into another package (presumably the app).

    // self-imports are legal in the app tree, even for v2 packages
    if (packageName === pkg.name) {
      return specifier;
    }

    // first try to resolve from the destination package
    if (isResolvable(packageName, relocatedPkg)) {
      if (!pkg.meta['auto-upgraded']) {
        throw new Error(
          `${pkg.name} is trying to import ${packageName} from within its app tree. This is unsafe, because ${pkg.name} can't control which dependencies are resolvable from the app`
        );
      }
      return specifier;
    } else {
      // second try to resolve from the source package
      let targetPkg = isResolvable(packageName, pkg);
      if (targetPkg) {
        if (!pkg.meta['auto-upgraded']) {
          throw new Error(
            `${pkg.name} is trying to import ${packageName} from within its app tree. This is unsafe, because ${pkg.name} can't control which dependencies are resolvable from the app`
          );
        }
        // we found it, but we need to rewrite it because it's not really going to
        // resolve from where its sitting
        return explicitRelative(dirname(sourceFile.name), specifier.replace(packageName, targetPkg.root));
      }
    }
  } else {
    if (isResolvable(packageName, pkg)) {
      if (!pkg.meta['auto-upgraded'] && !reliablyResolvable(pkg, packageName)) {
        throw new Error(
          `${pkg.name} is trying to import from ${packageName} but that is not one of its explicit dependencies`
        );
      }
      return specifier;
    }
  }

  // auto-upgraded packages can fall back to the set of known active addons
  if (pkg.meta['auto-upgraded'] && opts.activeAddons[packageName]) {
    return explicitRelative(dirname(sourceFile.name), specifier.replace(packageName, opts.activeAddons[packageName]));
  }

  if (pkg.meta['auto-upgraded']) {
    // auto-upgraded packages can fall back to attempting to find dependencies at
    // runtime. Native v2 packages can only get this behavior in the
    // isExplicitlyExternal case above because they need to explicitly ask for
    // externals.
    return makeExternal(specifier, sourceFile, opts);
  } else {
    // native v2 packages don't automatically externalize *everything* the way
    // auto-upgraded packages do, but they still externalize known and approved
    // ember virtual packages (like @ember/component)
    if (emberVirtualPackages.has(packageName)) {
      return makeExternal(specifier, sourceFile, opts);
    }
  }

  // non-resolvable imports in dynamic positions become runtime errors, not
  // build-time errors, so we emit the runtime error module here before the
  // stage3 packager has a chance to see the missing module. (Maybe some stage3
  // packagers will have this behavior by default, because it would make sense,
  // but webpack at least does not.)
  if (isDynamic) {
    return makeMissingModule(specifier, sourceFile, opts);
  }

  // this is falling through with the original specifier which was
  // non-resolvable, which will presumably cause a static build error in stage3.
  return specifier;
}

function makeMissingModule(specifier: string, sourceFile: AdjustFile, opts: Options): string {
  let target = join(opts.externalsDir, specifier + '.js');
  outputFileSync(
    target,
    dynamicMissingModule({
      moduleName: specifier,
    })
  );
  return explicitRelative(dirname(sourceFile.name), target.slice(0, -3));
}

function makeExternal(specifier: string, sourceFile: AdjustFile, opts: Options): string {
  let target = join(opts.externalsDir, specifier + '.js');
  outputFileSync(
    target,
    externalTemplate({
      runtimeName: specifier,
    })
  );
  return explicitRelative(dirname(sourceFile.name), target.slice(0, -3));
}

export default function main(babel: typeof Babel) {
  let t = babel.types;
  return {
    visitor: {
      Program: {
        enter(path: NodePath<t.Program>, state: State) {
          let opts = ensureOpts(state);
          state.adjustFile = new AdjustFile(path.hub.file.opts.filename, opts.relocatedFiles);
          let adder = new ImportUtil(t, path);
          addExtraImports(adder, t, path, opts.extraImports);
        },
        exit(path: NodePath<t.Program>, state: State) {
          for (let child of path.get('body')) {
            if (child.isImportDeclaration() || child.isExportNamedDeclaration() || child.isExportAllDeclaration()) {
              rewriteTopLevelImport(t, child, state);
            }
          }
        },
      },
      CallExpression(path: NodePath<t.CallExpression>, state: State) {
        if (isImportSyncExpression(t, path) || isDynamicImportExpression(t, path)) {
          const [source] = path.get('arguments');
          let opts = ensureOpts(state);
          let specifier = adjustSpecifier((source.node as any).value, state.adjustFile, opts, true);
          source.replaceWith(t.stringLiteral(specifier));
          return;
        }

        // Should/can we make this early exit when the first define was found?
        if (!isDefineExpression(t, path)) {
          return;
        }

        let pkg = state.adjustFile.owningPackage();
        if (pkg && pkg.isV2Ember() && !pkg.meta['auto-upgraded']) {
          throw new Error(
            `The file ${state.adjustFile.originalFile} in package ${pkg.name} tried to use AMD define. Native V2 Ember addons are forbidden from using AMD define, they must use ECMA export only.`
          );
        }

        let opts = ensureOpts(state);

        const dependencies = path.node.arguments[1];

        const specifiers = dependencies.elements.slice();
        specifiers.push(path.node.arguments[0]);

        for (let source of specifiers) {
          if (!source) {
            continue;
          }

          if (source.type !== 'StringLiteral') {
            throw path.buildCodeFrameError(`expected only string literal arguments`);
          }

          if (source.value === 'exports' || source.value === 'require') {
            // skip "special" AMD dependencies
            continue;
          }

          let specifier = adjustSpecifier(source.value, state.adjustFile, opts, false);

          if (specifier !== source.value) {
            source.value = specifier;
          }
        }
      },
    },
  };
}

function rewriteTopLevelImport(
  t: BabelTypes,
  path: NodePath<t.ImportDeclaration | t.ExportNamedDeclaration | t.ExportAllDeclaration>,
  state: State
) {
  let opts = ensureOpts(state);
  const { source } = path.node;
  if (source === null || source === undefined) {
    return;
  }

  if (opts.emberNeedsModulesPolyfill && path.isImportDeclaration()) {
    let replacement = handleImportDeclaration(t, path);
    if (replacement) {
      path.replaceWith(replacement);
      return;
    }
  }

  let specifier = adjustSpecifier(source.value, state.adjustFile, opts, false);
  if (specifier !== source.value) {
    source.value = specifier;
  }
}

(main as any).baseDir = function () {
  return join(__dirname, '..');
};

function addExtraImports(
  adder: ImportUtil,
  t: BabelTypes,
  path: NodePath<t.Program>,
  extraImports: Required<Options>['extraImports']
) {
  for (let { absPath, target, runtimeName } of extraImports) {
    if (absPath === path.hub.file.opts.filename) {
      if (runtimeName) {
        path.node.body.unshift(amdDefine(t, adder, path, target, runtimeName));
      } else {
        adder.importForSideEffect(target);
      }
    }
  }
}

function amdDefine(t: BabelTypes, adder: ImportUtil, path: NodePath<t.Program>, target: string, runtimeName: string) {
  let value = t.callExpression(adder.import(path, '@embroider/macros', 'importSync'), [t.stringLiteral(target)]);
  return t.expressionStatement(
    t.callExpression(t.memberExpression(t.identifier('window'), t.identifier('define')), [
      t.stringLiteral(runtimeName),
      t.functionExpression(null, [], t.blockStatement([t.returnStatement(value)])),
    ])
  );
}

class AdjustFile {
  readonly originalFile: string;

  constructor(public name: string, relocatedFiles: Options['relocatedFiles']) {
    if (!name) {
      throw new Error(`bug: adjust-imports plugin was run without a filename`);
    }
    this.originalFile = relocatedFiles[name] || name;
  }

  get isRelocated() {
    return this.originalFile !== this.name;
  }

  @Memoize()
  owningPackage(): Package | undefined {
    return packageCache.ownerOfFile(this.originalFile);
  }

  @Memoize()
  relocatedIntoPackage(): Package | undefined {
    if (this.isRelocated) {
      return packageCache.ownerOfFile(this.name);
    }
  }
}

function ensureOpts(state: State): Options {
  let { opts } = state;
  if ('adjustImportsOptionsPath' in opts) {
    // eslint-disable-next-line @typescript-eslint/no-require-imports
    return (state.opts = { ...require(opts.adjustImportsOptionsPath), ...require(opts.relocatedFilesPath) });
  }
  return opts;
}

// we don't want to allow things that resolve only by accident that are likely
// to break in other setups. For example: import your dependencies'
// dependencies, or importing your own name from within a monorepo (which will
// work because of the symlinking) without setting up "exports" (which makes
// your own name reliably resolvable)
function reliablyResolvable(pkg: V2Package, packageName: string) {
  if (pkg.hasDependency(packageName)) {
    return true;
  }

  if (pkg.name === packageName && pkg.packageJSON.exports) {
    return true;
  }

  if (emberVirtualPeerDeps.has(packageName)) {
    return true;
  }

  return false;
}