diff options
Diffstat (limited to 'node_modules/sucrase/dist/identifyShadowedGlobals.js')
| -rw-r--r-- | node_modules/sucrase/dist/identifyShadowedGlobals.js | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/node_modules/sucrase/dist/identifyShadowedGlobals.js b/node_modules/sucrase/dist/identifyShadowedGlobals.js new file mode 100644 index 0000000..41c8eef --- /dev/null +++ b/node_modules/sucrase/dist/identifyShadowedGlobals.js @@ -0,0 +1,98 @@ +"use strict";Object.defineProperty(exports, "__esModule", {value: true}); + + + +var _tokenizer = require('./parser/tokenizer'); + +var _types = require('./parser/tokenizer/types'); + + +/** + * Traverse the given tokens and modify them if necessary to indicate that some names shadow global + * variables. + */ + function identifyShadowedGlobals( + tokens, + scopes, + globalNames, +) { + if (!hasShadowedGlobals(tokens, globalNames)) { + return; + } + markShadowedGlobals(tokens, scopes, globalNames); +} exports.default = identifyShadowedGlobals; + +/** + * We can do a fast up-front check to see if there are any declarations to global names. If not, + * then there's no point in computing scope assignments. + */ +// Exported for testing. + function hasShadowedGlobals(tokens, globalNames) { + for (const token of tokens.tokens) { + if ( + token.type === _types.TokenType.name && + !token.isType && + _tokenizer.isNonTopLevelDeclaration.call(void 0, token) && + globalNames.has(tokens.identifierNameForToken(token)) + ) { + return true; + } + } + return false; +} exports.hasShadowedGlobals = hasShadowedGlobals; + +function markShadowedGlobals( + tokens, + scopes, + globalNames, +) { + const scopeStack = []; + let scopeIndex = scopes.length - 1; + // Scopes were generated at completion time, so they're sorted by end index, so we can maintain a + // good stack by going backwards through them. + for (let i = tokens.tokens.length - 1; ; i--) { + while (scopeStack.length > 0 && scopeStack[scopeStack.length - 1].startTokenIndex === i + 1) { + scopeStack.pop(); + } + while (scopeIndex >= 0 && scopes[scopeIndex].endTokenIndex === i + 1) { + scopeStack.push(scopes[scopeIndex]); + scopeIndex--; + } + // Process scopes after the last iteration so we can make sure we pop all of them. + if (i < 0) { + break; + } + + const token = tokens.tokens[i]; + const name = tokens.identifierNameForToken(token); + if (scopeStack.length > 1 && !token.isType && token.type === _types.TokenType.name && globalNames.has(name)) { + if (_tokenizer.isBlockScopedDeclaration.call(void 0, token)) { + markShadowedForScope(scopeStack[scopeStack.length - 1], tokens, name); + } else if (_tokenizer.isFunctionScopedDeclaration.call(void 0, token)) { + let stackIndex = scopeStack.length - 1; + while (stackIndex > 0 && !scopeStack[stackIndex].isFunctionScope) { + stackIndex--; + } + if (stackIndex < 0) { + throw new Error("Did not find parent function scope."); + } + markShadowedForScope(scopeStack[stackIndex], tokens, name); + } + } + } + if (scopeStack.length > 0) { + throw new Error("Expected empty scope stack after processing file."); + } +} + +function markShadowedForScope(scope, tokens, name) { + for (let i = scope.startTokenIndex; i < scope.endTokenIndex; i++) { + const token = tokens.tokens[i]; + if ( + (token.type === _types.TokenType.name || token.type === _types.TokenType.jsxName) && + tokens.identifierNameForToken(token) === name + ) { + token.shadowsGlobal = true; + } + } +} |