fix: make errors serializable (#516)

Author: alexander-akait

lint-staged.config.js

@@ -1,4 +1,4 @@
 module.exports = {
- "*": ["prettier --write --ignore-unknown", "cspell"],
+ "*": ["prettier --write --ignore-unknown", "cspell --no-must-find-files"],
  "*.{js}": ["eslint --cache --fix"],
 };

src/LessError.js

@@ -6,8 +6,8 @@ import {
  isUnsupportedUrl,
  normalizeSourceMap,
  getLessImplementation,
+ errorFactory,
 } from "./utils";
-import LessError from "./LessError";
 
 async function lessLoader(source) {
  const options = this.getOptions(schema);
@@ -78,7 +78,7 @@ async function lessLoader(source) {
  this.addDependency(path.normalize(error.filename));
  }
 
- callback(new LessError(error));
+ callback(errorFactory(error));
 
  return;
  } finally {

src/index.js

@@ -240,9 +240,46 @@ function getLessImplementation(loaderContext, implementation) {
  return resolvedImplementation;
 }
 
+function getFileExcerptIfPossible(error) {
+ if (typeof error.extract === "undefined") {
+ return [];
+ }
+
+ const excerpt = error.extract.slice(0, 2);
+ const column = Math.max(error.column - 1, 0);
+
+ if (typeof excerpt[0] === "undefined") {
+ excerpt.shift();
+ }
+
+ excerpt.push(`${new Array(column).join(" ")}^`);
+
+ return excerpt;
+}
+
+function errorFactory(error) {
+ const message = [
+ "\n",
+ ...getFileExcerptIfPossible(error),
+ error.message.charAt(0).toUpperCase() + error.message.slice(1),
+ error.filename
+ ? ` Error in ${path.normalize(error.filename)} (line ${
+ error.line
+ }, column ${error.column})`
+ : "",
+ ].join("\n");
+
+ const obj = new Error(message, { cause: error });
+
+ obj.stack = null;
+
+ return obj;
+}
+
 export {
  getLessOptions,
  isUnsupportedUrl,
  normalizeSourceMap,
  getLessImplementation,
+ errorFactory,
 };

src/utils.js

@@ -431,6 +431,15 @@ exports[`loader should resolve unresolved url with alias: errors 1`] = `[]`;
 
 exports[`loader should resolve unresolved url with alias: warnings 1`] = `[]`;
 
+exports[`loader should throw an error: errors 1`] = `
+[
+ "ModuleBuildError: Module build failed (from \`replaced original path\`):
+",
+]
+`;
+
+exports[`loader should throw an error: warnings 1`] = `[]`;
+
 exports[`loader should transform urls: css 1`] = `
 ".img4 {
  background: url(folder/img.jpg);

test/__snapshots__/loader.test.js.snap

@@ -0,0 +1 @@
+broken;

test/fixtures/broken.less

@@ -991,4 +991,13 @@ describe("loader", () => {
  expect(getWarnings(stats)).toMatchSnapshot("warnings");
  expect(getErrors(stats)).toMatchSnapshot("errors");
  });
+
+ it("should throw an error", async () => {
+ const testId = "./broken.less";
+ const compiler = getCompiler(testId);
+ const stats = await compile(compiler);
+
+ expect(getWarnings(stats)).toMatchSnapshot("warnings");
+ expect(getErrors(stats)).toMatchSnapshot("errors");
+ });
 });