Function getPathsToTry

src/try-path.ts:18–56

(
  extensions: ReadonlyArray<string>,
  absolutePathMappings: ReadonlyArray<MappingEntry>,
  requestedModule: string
)

 * 4. Check for files named as request ending in "index" with any of the extensions.
 */
export function getPathsToTry(
  extensions: ReadonlyArray<string>,
  absolutePathMappings: ReadonlyArray<MappingEntry>,
  requestedModule: string
): ReadonlyArray<TryPath> | undefined {
  if (!absolutePathMappings || !requestedModule || requestedModule[0] === ".") {
    return undefined;
  }

  const pathsToTry: Array<TryPath> = [];
  for (const entry of absolutePathMappings) {
    const starMatch =
      entry.pattern === requestedModule
        ? ""
        : matchStar(entry.pattern, requestedModule);
    if (starMatch !== undefined) {
      for (const physicalPathPattern of entry.paths) {
        const physicalPath = physicalPathPattern.replace("*", starMatch);
        pathsToTry.push({ type: "file", path: physicalPath });
        pathsToTry.push(
          ...extensions.map(
            (e) => ({ type: "extension", path: physicalPath + e } as TryPath)
          )
        );
        pathsToTry.push({
          type: "package",
          path: path.join(physicalPath, "/package.json"),
        });
        const indexPath = path.join(physicalPath, "/index");
        pathsToTry.push(
          ...extensions.map(
            (e) => ({ type: "index", path: indexPath + e } as TryPath)
          )
        );
      }
    }
  }
  return pathsToTry.length === 0 ? undefined : pathsToTry;
}

// Not sure why we don't just return the full found path?
export function getStrippedPath(tryPath: TryPath): string {