react-native-builder-bob/lib/src/utils/updateSourceMap.js

CLI to build JavaScript files for React Native libraries

import { decode, encode } from '@jridgewell/sourcemap-codec';
import { type } from 'arktype';
import fs from 'fs-extra';
const sourceMap = type({
    version: 'number',
    file: 'string?',
    sourceRoot: 'string?',
    sources: 'string[]',
    names: 'string[]?',
    mappings: 'string',
    sourcesContent: 'string[]?',
}).onDeepUndeclaredKey('ignore');
export const updateSourceMap = async ({ filepath, replacements, sourceFile, }) => {
    const map = sourceMap.assert(await fs.readJSON(filepath));
    const lines = decode(map.mappings);
    let changed = false;
    // Sort replacements in reverse order
    // We apply replacements from the end, so earlier offsets stay valid
    // So we won't have to keep track of changes as we go
    const sortedReplacements = [...replacements].sort((a, b) => b.start - a.start);
    for (const replacement of sortedReplacements) {
        // Get line and column of the replacements from the absolute character offsets
        const start = sourceFile.getLineAndCharacterOfPosition(replacement.start);
        const end = sourceFile.getLineAndCharacterOfPosition(replacement.end);
        // We add file extensions which only affect single lines
        // So we don't handle multi-line replacements to avoid complexity
        if (start.line !== end.line) {
            throw new Error('Source map replacement spanning multiple lines is not supported.');
        }
        // Get the amount of characters added or removed by the replacement
        // e.g. `./foo` -> `./foo.js` adds 3 characters, so delta is 3
        const delta = replacement.value.length - (replacement.end - replacement.start);
        if (delta === 0) {
            continue;
        }
        const segments = lines[start.line];
        if (segments) {
            for (const segment of segments) {
                // If a mapping points to text at or after the end of the replaced import string,
                // move that mapping by the same number of characters the replacement added or removed
                if (segment[0] >= end.character) {
                    segment[0] += delta;
                    changed = true;
                }
            }
        }
    }
    if (!changed) {
        return;
    }
    await fs.writeJSON(filepath, {
        ...map,
        mappings: encode(lines),
    });
};
//# sourceMappingURL=updateSourceMap.js.map