react/scripts/shared/evalToString.js

61 lines
1.7 KiB
JavaScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
*/
'use strict';
function evalStringConcat(ast /*: Object */) /*: string */ {
switch (ast.type) {
case 'StringLiteral':
case 'Literal': // ESLint
return ast.value;
case 'BinaryExpression': // `+`
if (ast.operator !== '+') {
throw new Error('Unsupported binary operator ' + ast.operator);
}
return evalStringConcat(ast.left) + evalStringConcat(ast.right);
default:
throw new Error('Unsupported type ' + ast.type);
}
}
exports.evalStringConcat = evalStringConcat;
function evalStringAndTemplateConcat(
ast /*: Object */,
args /*: Array<mixed> */
) /*: string */ {
switch (ast.type) {
case 'StringLiteral':
return ast.value;
case 'BinaryExpression': // `+`
if (ast.operator !== '+') {
throw new Error('Unsupported binary operator ' + ast.operator);
}
return (
evalStringAndTemplateConcat(ast.left, args) +
evalStringAndTemplateConcat(ast.right, args)
);
case 'TemplateLiteral': {
let elements = [];
for (let i = 0; i < ast.quasis.length; i++) {
const elementNode = ast.quasis[i];
if (elementNode.type !== 'TemplateElement') {
throw new Error('Unsupported type ' + ast.type);
}
elements.push(elementNode.value.cooked);
}
args.push(...ast.expressions);
return elements.join('%s');
}
default:
// Anything that's not a string is interpreted as an argument.
args.push(ast);
return '%s';
}
}
exports.evalStringAndTemplateConcat = evalStringAndTemplateConcat;