fix: Enable cache with externalDependencies

src/cache.js

@@ -90,9 +90,16 @@ const handleCache = async function (directory, params) {
  cacheIdentifier,
  cacheDirectory,
  cacheCompression,
+ cachedDepMtimes,
  } = params;
 
- const file = path.join(directory, filename(source, cacheIdentifier, options));
+ const file = path.join(
+ directory,
+ filename(source, cacheIdentifier, {
+ options,
+ __cachedDepMtimes: cachedDepMtimes,
+ }),
+ );
 
  try {
  // No errors mean that the file was previously cached
@@ -119,19 +126,15 @@ const handleCache = async function (directory, params) {
  // return it to the user asap and write it in cache
  const result = await transform(source, options);
 
- // Do not cache if there are external dependencies,
- // since they might change and we cannot control it.
- if (!result.externalDependencies.length) {
- try {
- await write(file, cacheCompression, result);
- } catch (err) {
- if (fallback) {
- // Fallback to tmpdir if node_modules folder not writable
- return handleCache(os.tmpdir(), params);
- }
-
- throw err;
+ try {
+ await write(file, cacheCompression, result);
+ } catch (err) {
+ if (fallback) {
+ // Fallback to tmpdir if node_modules folder not writable
+ return handleCache(os.tmpdir(), params);
  }
+
+ throw err;
  }
 
  return result;

src/index.js

@@ -26,6 +26,7 @@ const injectCaller = require("./injectCaller");
 const schema = require("./schema");
 
 const { isAbsolute } = require("path");
+const fs = require("fs");
 const validateOptions = require("schema-utils").validate;
 
 function subscribe(subscriber, metadata, context) {
@@ -39,19 +40,22 @@ module.exports.custom = makeLoader;
 
 function makeLoader(callback) {
  const overrides = callback ? callback(babel) : undefined;
+ const data = {
+ cachedDepMtimes: { __proto__: null },
+ };
 
  return function (source, inputSourceMap) {
  // Make the loader async
  const callback = this.async();
 
- loader.call(this, source, inputSourceMap, overrides).then(
+ loader.call(this, source, inputSourceMap, overrides, data).then(
  args => callback(null, ...args),
  err => callback(err),
  );
  };
 }
 
-async function loader(source, inputSourceMap, overrides) {
+async function loader(source, inputSourceMap, overrides, data) {
  const filename = this.resourcePath;
 
  let loaderOptions = this.getOptions();
@@ -185,13 +189,24 @@ async function loader(source, inputSourceMap, overrides) {
 
  let result;
  if (cacheDirectory) {
+ const cachedDepMtimes = [];
+ for (const dep of Object.keys(data.cachedDepMtimes)) {
+ let mtime = 0;
+ try {
+ mtime = fs.statSync(dep).mtime;
+ } catch (error) {}
+ cachedDepMtimes.push(dep + mtime);
+ }
+ cachedDepMtimes.sort();
+
  result = await cache({
  source,
  options,
  transform,
  cacheDirectory,
  cacheIdentifier,
  cacheCompression,
+ cachedDepMtimes,
  });
  } else {
  result = await transform(source, options);
@@ -212,7 +227,17 @@ async function loader(source, inputSourceMap, overrides) {
 
  const { code, map, metadata, externalDependencies } = result;
 
- externalDependencies?.forEach(dep => this.addDependency(dep));
+ externalDependencies?.forEach(dep => {
+ if (data.cachedDepMtimes[dep] == null) {
+ let mtime = 0;
+ try {
+ mtime = fs.statSync(dep).mtime;
+ } catch (error) {}
+ data.cachedDepMtimes[dep] = mtime;
+ }
+ this.addDependency(dep);
+ });
+
  metadataSubscribers.forEach(subscriber => {
  subscribe(subscriber, metadata, this);
  });