lookupPosition(): { absolutePath: string; line: number; col: number; sourceText: string | null; }
| null
Returns the original source position for a generated (line, col) pair.
Both coordinates are 1-based (the format Chrome uses in Error.stack).
Returns null when the position cannot be mapped.
import * as SourceMap from './source-map.ts'; const decoder = SourceMap.parse('{"sources":["../test/login-test.ts"],"mappings":"AAAA"}', '/proj/tmp'); SourceMap.lookupPosition(decoder, 1, 1); // { absolutePath: '/proj/test/login-test.ts', line: 1, col: 1, sourceText: null } SourceMap.lookupPosition(decoder, 99, 1); // null — no mapping for that generated line