1 files changed, 415 insertions, 0 deletions
diff --git a/node_modules/sucrase/dist/transformers/ESMImportTransformer.js b/node_modules/sucrase/dist/transformers/ESMImportTransformer.js
new file mode 100644
index 0000000..d89e5ea
--- /dev/null
+++ b/node_modules/sucrase/dist/transformers/ESMImportTransformer.js
@@ -0,0 +1,415 @@
+"use strict";Object.defineProperty(exports, "__esModule", {value: true}); function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+
+var _keywords = require('../parser/tokenizer/keywords');
+var _types = require('../parser/tokenizer/types');
+
+var _elideImportEquals = require('../util/elideImportEquals'); var _elideImportEquals2 = _interopRequireDefault(_elideImportEquals);
+
+
+
+var _getDeclarationInfo = require('../util/getDeclarationInfo'); var _getDeclarationInfo2 = _interopRequireDefault(_getDeclarationInfo);
+var _getImportExportSpecifierInfo = require('../util/getImportExportSpecifierInfo'); var _getImportExportSpecifierInfo2 = _interopRequireDefault(_getImportExportSpecifierInfo);
+var _getNonTypeIdentifiers = require('../util/getNonTypeIdentifiers');
+var _isExportFrom = require('../util/isExportFrom'); var _isExportFrom2 = _interopRequireDefault(_isExportFrom);
+var _removeMaybeImportAttributes = require('../util/removeMaybeImportAttributes');
+var _shouldElideDefaultExport = require('../util/shouldElideDefaultExport'); var _shouldElideDefaultExport2 = _interopRequireDefault(_shouldElideDefaultExport);
+
+var _Transformer = require('./Transformer'); var _Transformer2 = _interopRequireDefault(_Transformer);
+
+/**
+ * Class for editing import statements when we are keeping the code as ESM. We still need to remove
+ * type-only imports in TypeScript and Flow.
+ */
+ class ESMImportTransformer extends _Transformer2.default {
+  
+  
+  
+
+  constructor(
+     tokens,
+     nameManager,
+     helperManager,
+     reactHotLoaderTransformer,
+     isTypeScriptTransformEnabled,
+     isFlowTransformEnabled,
+     keepUnusedImports,
+    options,
+  ) {
+    super();this.tokens = tokens;this.nameManager = nameManager;this.helperManager = helperManager;this.reactHotLoaderTransformer = reactHotLoaderTransformer;this.isTypeScriptTransformEnabled = isTypeScriptTransformEnabled;this.isFlowTransformEnabled = isFlowTransformEnabled;this.keepUnusedImports = keepUnusedImports;;
+    this.nonTypeIdentifiers =
+      isTypeScriptTransformEnabled && !keepUnusedImports
+        ? _getNonTypeIdentifiers.getNonTypeIdentifiers.call(void 0, tokens, options)
+        : new Set();
+    this.declarationInfo =
+      isTypeScriptTransformEnabled && !keepUnusedImports
+        ? _getDeclarationInfo2.default.call(void 0, tokens)
+        : _getDeclarationInfo.EMPTY_DECLARATION_INFO;
+    this.injectCreateRequireForImportRequire = Boolean(options.injectCreateRequireForImportRequire);
+  }
+
+  process() {
+    // TypeScript `import foo = require('foo');` should always just be translated to plain require.
+    if (this.tokens.matches3(_types.TokenType._import, _types.TokenType.name, _types.TokenType.eq)) {
+      return this.processImportEquals();
+    }
+    if (
+      this.tokens.matches4(_types.TokenType._import, _types.TokenType.name, _types.TokenType.name, _types.TokenType.eq) &&
+      this.tokens.matchesContextualAtIndex(this.tokens.currentIndex() + 1, _keywords.ContextualKeyword._type)
+    ) {
+      // import type T = require('T')
+      this.tokens.removeInitialToken();
+      // This construct is always exactly 8 tokens long, so remove the 7 remaining tokens.
+      for (let i = 0; i < 7; i++) {
+        this.tokens.removeToken();
+      }
+      return true;
+    }
+    if (this.tokens.matches2(_types.TokenType._export, _types.TokenType.eq)) {
+      this.tokens.replaceToken("module.exports");
+      return true;
+    }
+    if (
+      this.tokens.matches5(_types.TokenType._export, _types.TokenType._import, _types.TokenType.name, _types.TokenType.name, _types.TokenType.eq) &&
+      this.tokens.matchesContextualAtIndex(this.tokens.currentIndex() + 2, _keywords.ContextualKeyword._type)
+    ) {
+      // export import type T = require('T')
+      this.tokens.removeInitialToken();
+      // This construct is always exactly 9 tokens long, so remove the 8 remaining tokens.
+      for (let i = 0; i < 8; i++) {
+        this.tokens.removeToken();
+      }
+      return true;
+    }
+    if (this.tokens.matches1(_types.TokenType._import)) {
+      return this.processImport();
+    }
+    if (this.tokens.matches2(_types.TokenType._export, _types.TokenType._default)) {
+      return this.processExportDefault();
+    }
+    if (this.tokens.matches2(_types.TokenType._export, _types.TokenType.braceL)) {
+      return this.processNamedExports();
+    }
+    if (
+      this.tokens.matches2(_types.TokenType._export, _types.TokenType.name) &&
+      this.tokens.matchesContextualAtIndex(this.tokens.currentIndex() + 1, _keywords.ContextualKeyword._type)
+    ) {
+      // export type {a};
+      // export type {a as b};
+      // export type {a} from './b';
+      // export type * from './b';
+      // export type * as ns from './b';
+      this.tokens.removeInitialToken();
+      this.tokens.removeToken();
+      if (this.tokens.matches1(_types.TokenType.braceL)) {
+        while (!this.tokens.matches1(_types.TokenType.braceR)) {
+          this.tokens.removeToken();
+        }
+        this.tokens.removeToken();
+      } else {
+        // *
+        this.tokens.removeToken();
+        if (this.tokens.matches1(_types.TokenType._as)) {
+          // as
+          this.tokens.removeToken();
+          // ns
+          this.tokens.removeToken();
+        }
+      }
+      // Remove type re-export `... } from './T'`
+      if (
+        this.tokens.matchesContextual(_keywords.ContextualKeyword._from) &&
+        this.tokens.matches1AtIndex(this.tokens.currentIndex() + 1, _types.TokenType.string)
+      ) {
+        this.tokens.removeToken();
+        this.tokens.removeToken();
+        _removeMaybeImportAttributes.removeMaybeImportAttributes.call(void 0, this.tokens);
+      }
+      return true;
+    }
+    return false;
+  }
+
+   processImportEquals() {
+    const importName = this.tokens.identifierNameAtIndex(this.tokens.currentIndex() + 1);
+    if (this.shouldAutomaticallyElideImportedName(importName)) {
+      // If this name is only used as a type, elide the whole import.
+      _elideImportEquals2.default.call(void 0, this.tokens);
+    } else if (this.injectCreateRequireForImportRequire) {
+      // We're using require in an environment (Node ESM) that doesn't provide
+      // it as a global, so generate a helper to import it.
+      // import -> const
+      this.tokens.replaceToken("const");
+      // Foo
+      this.tokens.copyToken();
+      // =
+      this.tokens.copyToken();
+      // require
+      this.tokens.replaceToken(this.helperManager.getHelperName("require"));
+    } else {
+      // Otherwise, just switch `import` to `const`.
+      this.tokens.replaceToken("const");
+    }
+    return true;
+  }
+
+   processImport() {
+    if (this.tokens.matches2(_types.TokenType._import, _types.TokenType.parenL)) {
+      // Dynamic imports don't need to be transformed.
+      return false;
+    }
+
+    const snapshot = this.tokens.snapshot();
+    const allImportsRemoved = this.removeImportTypeBindings();
+    if (allImportsRemoved) {
+      this.tokens.restoreToSnapshot(snapshot);
+      while (!this.tokens.matches1(_types.TokenType.string)) {
+        this.tokens.removeToken();
+      }
+      this.tokens.removeToken();
+      _removeMaybeImportAttributes.removeMaybeImportAttributes.call(void 0, this.tokens);
+      if (this.tokens.matches1(_types.TokenType.semi)) {
+        this.tokens.removeToken();
+      }
+    }
+    return true;
+  }
+
+  /**
+   * Remove type bindings from this import, leaving the rest of the import intact.
+   *
+   * Return true if this import was ONLY types, and thus is eligible for removal. This will bail out
+   * of the replacement operation, so we can return early here.
+   */
+   removeImportTypeBindings() {
+    this.tokens.copyExpectedToken(_types.TokenType._import);
+    if (
+      this.tokens.matchesContextual(_keywords.ContextualKeyword._type) &&
+      !this.tokens.matches1AtIndex(this.tokens.currentIndex() + 1, _types.TokenType.comma) &&
+      !this.tokens.matchesContextualAtIndex(this.tokens.currentIndex() + 1, _keywords.ContextualKeyword._from)
+    ) {
+      // This is an "import type" statement, so exit early.
+      return true;
+    }
+
+    if (this.tokens.matches1(_types.TokenType.string)) {
+      // This is a bare import, so we should proceed with the import.
+      this.tokens.copyToken();
+      return false;
+    }
+
+    // Skip the "module" token in import reflection.
+    if (
+      this.tokens.matchesContextual(_keywords.ContextualKeyword._module) &&
+      this.tokens.matchesContextualAtIndex(this.tokens.currentIndex() + 2, _keywords.ContextualKeyword._from)
+    ) {
+      this.tokens.copyToken();
+    }
+
+    let foundNonTypeImport = false;
+    let foundAnyNamedImport = false;
+    let needsComma = false;
+
+    // Handle default import.
+    if (this.tokens.matches1(_types.TokenType.name)) {
+      if (this.shouldAutomaticallyElideImportedName(this.tokens.identifierName())) {
+        this.tokens.removeToken();
+        if (this.tokens.matches1(_types.TokenType.comma)) {
+          this.tokens.removeToken();
+        }
+      } else {
+        foundNonTypeImport = true;
+        this.tokens.copyToken();
+        if (this.tokens.matches1(_types.TokenType.comma)) {
+          // We're in a statement like:
+          // import A, * as B from './A';
+          // or
+          // import A, {foo} from './A';
+          // where the `A` is being kept. The comma should be removed if an only
+          // if the next part of the import statement is elided, but that's hard
+          // to determine at this point in the code. Instead, always remove it
+          // and set a flag to add it back if necessary.
+          needsComma = true;
+          this.tokens.removeToken();
+        }
+      }
+    }
+
+    if (this.tokens.matches1(_types.TokenType.star)) {
+      if (this.shouldAutomaticallyElideImportedName(this.tokens.identifierNameAtRelativeIndex(2))) {
+        this.tokens.removeToken();
+        this.tokens.removeToken();
+        this.tokens.removeToken();
+      } else {
+        if (needsComma) {
+          this.tokens.appendCode(",");
+        }
+        foundNonTypeImport = true;
+        this.tokens.copyExpectedToken(_types.TokenType.star);
+        this.tokens.copyExpectedToken(_types.TokenType.name);
+        this.tokens.copyExpectedToken(_types.TokenType.name);
+      }
+    } else if (this.tokens.matches1(_types.TokenType.braceL)) {
+      if (needsComma) {
+        this.tokens.appendCode(",");
+      }
+      this.tokens.copyToken();
+      while (!this.tokens.matches1(_types.TokenType.braceR)) {
+        foundAnyNamedImport = true;
+        const specifierInfo = _getImportExportSpecifierInfo2.default.call(void 0, this.tokens);
+        if (
+          specifierInfo.isType ||
+          this.shouldAutomaticallyElideImportedName(specifierInfo.rightName)
+        ) {
+          while (this.tokens.currentIndex() < specifierInfo.endIndex) {
+            this.tokens.removeToken();
+          }
+          if (this.tokens.matches1(_types.TokenType.comma)) {
+            this.tokens.removeToken();
+          }
+        } else {
+          foundNonTypeImport = true;
+          while (this.tokens.currentIndex() < specifierInfo.endIndex) {
+            this.tokens.copyToken();
+          }
+          if (this.tokens.matches1(_types.TokenType.comma)) {
+            this.tokens.copyToken();
+          }
+        }
+      }
+      this.tokens.copyExpectedToken(_types.TokenType.braceR);
+    }
+
+    if (this.keepUnusedImports) {
+      return false;
+    }
+    if (this.isTypeScriptTransformEnabled) {
+      return !foundNonTypeImport;
+    } else if (this.isFlowTransformEnabled) {
+      // In Flow, unlike TS, `import {} from 'foo';` preserves the import.
+      return foundAnyNamedImport && !foundNonTypeImport;
+    } else {
+      return false;
+    }
+  }
+
+   shouldAutomaticallyElideImportedName(name) {
+    return (
+      this.isTypeScriptTransformEnabled &&
+      !this.keepUnusedImports &&
+      !this.nonTypeIdentifiers.has(name)
+    );
+  }
+
+   processExportDefault() {
+    if (
+      _shouldElideDefaultExport2.default.call(void 0, 
+        this.isTypeScriptTransformEnabled,
+        this.keepUnusedImports,
+        this.tokens,
+        this.declarationInfo,
+      )
+    ) {
+      // If the exported value is just an identifier and should be elided by TypeScript
+      // rules, then remove it entirely. It will always have the form `export default e`,
+      // where `e` is an identifier.
+      this.tokens.removeInitialToken();
+      this.tokens.removeToken();
+      this.tokens.removeToken();
+      return true;
+    }
+
+    const alreadyHasName =
+      this.tokens.matches4(_types.TokenType._export, _types.TokenType._default, _types.TokenType._function, _types.TokenType.name) ||
+      // export default async function
+      (this.tokens.matches5(_types.TokenType._export, _types.TokenType._default, _types.TokenType.name, _types.TokenType._function, _types.TokenType.name) &&
+        this.tokens.matchesContextualAtIndex(
+          this.tokens.currentIndex() + 2,
+          _keywords.ContextualKeyword._async,
+        )) ||
+      this.tokens.matches4(_types.TokenType._export, _types.TokenType._default, _types.TokenType._class, _types.TokenType.name) ||
+      this.tokens.matches5(_types.TokenType._export, _types.TokenType._default, _types.TokenType._abstract, _types.TokenType._class, _types.TokenType.name);
+
+    if (!alreadyHasName && this.reactHotLoaderTransformer) {
+      // This is a plain "export default E" statement and we need to assign E to a variable.
+      // Change "export default E" to "let _default; export default _default = E"
+      const defaultVarName = this.nameManager.claimFreeName("_default");
+      this.tokens.replaceToken(`let ${defaultVarName}; export`);
+      this.tokens.copyToken();
+      this.tokens.appendCode(` ${defaultVarName} =`);
+      this.reactHotLoaderTransformer.setExtractedDefaultExportName(defaultVarName);
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * Handle a statement with one of these forms:
+   * export {a, type b};
+   * export {c, type d} from 'foo';
+   *
+   * In both cases, any explicit type exports should be removed. In the first
+   * case, we also need to handle implicit export elision for names declared as
+   * types. In the second case, we must NOT do implicit named export elision,
+   * but we must remove the runtime import if all exports are type exports.
+   */
+   processNamedExports() {
+    if (!this.isTypeScriptTransformEnabled) {
+      return false;
+    }
+    this.tokens.copyExpectedToken(_types.TokenType._export);
+    this.tokens.copyExpectedToken(_types.TokenType.braceL);
+
+    const isReExport = _isExportFrom2.default.call(void 0, this.tokens);
+    let foundNonTypeExport = false;
+    while (!this.tokens.matches1(_types.TokenType.braceR)) {
+      const specifierInfo = _getImportExportSpecifierInfo2.default.call(void 0, this.tokens);
+      if (
+        specifierInfo.isType ||
+        (!isReExport && this.shouldElideExportedName(specifierInfo.leftName))
+      ) {
+        // Type export, so remove all tokens, including any comma.
+        while (this.tokens.currentIndex() < specifierInfo.endIndex) {
+          this.tokens.removeToken();
+        }
+        if (this.tokens.matches1(_types.TokenType.comma)) {
+          this.tokens.removeToken();
+        }
+      } else {
+        // Non-type export, so copy all tokens, including any comma.
+        foundNonTypeExport = true;
+        while (this.tokens.currentIndex() < specifierInfo.endIndex) {
+          this.tokens.copyToken();
+        }
+        if (this.tokens.matches1(_types.TokenType.comma)) {
+          this.tokens.copyToken();
+        }
+      }
+    }
+    this.tokens.copyExpectedToken(_types.TokenType.braceR);
+
+    if (!this.keepUnusedImports && isReExport && !foundNonTypeExport) {
+      // This is a type-only re-export, so skip evaluating the other module. Technically this
+      // leaves the statement as `export {}`, but that's ok since that's a no-op.
+      this.tokens.removeToken();
+      this.tokens.removeToken();
+      _removeMaybeImportAttributes.removeMaybeImportAttributes.call(void 0, this.tokens);
+    }
+
+    return true;
+  }
+
+  /**
+   * ESM elides all imports with the rule that we only elide if we see that it's
+   * a type and never see it as a value. This is in contrast to CJS, which
+   * elides imports that are completely unknown.
+   */
+   shouldElideExportedName(name) {
+    return (
+      this.isTypeScriptTransformEnabled &&
+      !this.keepUnusedImports &&
+      this.declarationInfo.typeDeclarations.has(name) &&
+      !this.declarationInfo.valueDeclarations.has(name)
+    );
+  }
+} exports.default = ESMImportTransformer;