Fail early, in modern GENERIC builds, if certain required browser functionality is missing (issue 11762)

external/dist/lib/README.md

@@ -3,5 +3,5 @@ pre-built library as found in e.g. the `/build`, `/web`, and `/image_decoders`
 folders in the root of this repository.
 
 Please note that the "lib" build target exists mostly to enable unit-testing in
-Node.js/Travis, and that you'll need to handle e.g. any Node.js dependencies
-yourself if using the files in this folder.
+Node.js/Travis, and that you'll need to handle e.g. any necessary polyfills
+and/or Node.js dependencies yourself if using the files in this folder.

gulpfile.js

@@ -1150,9 +1150,7 @@ gulp.task("jsdoc", function(done) {
  });
 });
 
-gulp.task(
- "lib",
- gulp.series("buildnumber", "default_preferences", function() {
+function buildLib(defines, dir) {
  // When we create a bundle, webpack is run on the source and it will replace
  // require with __webpack_require__. When we want to use the real require,
  // __non_webpack_require__ has to be used.
@@ -1171,8 +1169,7 @@ gulp.task(
  }
  function preprocess(content) {
  var skipBabel =
- bundleDefines.SKIP_BABEL ||
- /\/\*\s*no-babel-preset\s*\*\//.test(content);
+ bundleDefines.SKIP_BABEL || /\/\*\s*no-babel-preset\s*\*\//.test(content);
  content = preprocessor2.preprocessPDFJSCode(ctx, content);
  content = babel.transform(content, {
  sourceType: "module",
@@ -1190,19 +1187,14 @@ gulp.task(
  ],
  }).code;
  var removeCjsSrc = /^(var\s+\w+\s*=\s*(_interopRequireDefault\()?require\(".*?)(?:\/src)(\/[^"]*"\)\)?;)$/gm;
- content = content.replace(
- removeCjsSrc,
- (all, prefix, interop, suffix) => {
+ content = content.replace(removeCjsSrc, (all, prefix, interop, suffix) => {
  return prefix + suffix;
- }
- );
+ });
  return licenseHeaderLibre + content;
  }
  var babel = require("@babel/core");
  var versionInfo = getVersionJSON();
- var bundleDefines = builder.merge(DEFINES, {
- GENERIC: true,
- LIB: true,
+ var bundleDefines = builder.merge(defines, {
  BUNDLE_VERSION: versionInfo.version,
  BUNDLE_BUILD: versionInfo.commit,
  TESTING: process.env["TESTING"] === "true",
@@ -1235,7 +1227,28 @@ gulp.task(
  gulp.src("test/unit/*.js", { base: "." }),
  ])
  .pipe(transform("utf8", preprocess))
- .pipe(gulp.dest("build/lib/"));
+ .pipe(gulp.dest(dir));
+}
+
+gulp.task(
+ "lib",
+ gulp.series("buildnumber", "default_preferences", function() {
+ var defines = builder.merge(DEFINES, { GENERIC: true, LIB: true });
+
+ return buildLib(defines, "build/lib/");
+ })
+);
+
+gulp.task(
+ "lib-es5",
+ gulp.series("buildnumber", "default_preferences", function() {
+ var defines = builder.merge(DEFINES, {
+ GENERIC: true,
+ LIB: true,
+ SKIP_BABEL: false,
+ });
+
+ return buildLib(defines, "build/lib-es5/");
  })
 );
 
@@ -1371,7 +1384,7 @@ gulp.task("baseline", function(done) {
 
 gulp.task(
  "unittestcli",
- gulp.series("testing-pre", "lib", function(done) {
+ gulp.series("testing-pre", "lib-es5", function(done) {
  var options = [
  "node_modules/jasmine/bin/jasmine",
  "JASMINE_CONFIG_PATH=test/unit/clitests.json",

src/core/worker.js

@@ -136,6 +136,21 @@ var WorkerMessageHandler = {
  "; thus breaking e.g. `for...in` iteration of `Array`s."
  );
  }
+
+ // Ensure that (primarily) Node.js users won't accidentally attempt to use
+ // a non-translated/non-polyfilled build of the library, since that would
+ // quickly fail anyway because of missing functionality (such as e.g.
+ // `ReadableStream).
+ if (
+ (typeof PDFJSDev === "undefined" || PDFJSDev.test("SKIP_BABEL")) &&
+ typeof ReadableStream === "undefined"
+ ) {
+ throw new Error(
+ "The browser/environment lacks native support for critical " +
+ "functionality used by the PDF.js library (e.g. `ReadableStream`); " +
+ "please use an ES5-compatible build instead."
+ );
+ }
  }
 
  var docId = docParams.docId;

src/shared/compatibility.js

@@ -14,11 +14,9 @@
  */
 /* eslint no-var: error */
 
-// Skip compatibility checks for modern builds (unless we're running the
-// unit-tests in Node.js/Travis) and if we already ran the module.
+// Skip compatibility checks for modern builds and if we already ran the module.
 if (
- (typeof PDFJSDev === "undefined" ||
- PDFJSDev.test("!SKIP_BABEL || (LIB && TESTING)")) &&
+ (typeof PDFJSDev === "undefined" || !PDFJSDev.test("SKIP_BABEL")) &&
  (typeof globalThis === "undefined" || !globalThis._pdfjsCompatibilityChecked)
 ) {
  // Provides support for globalThis in legacy browsers.

test/unit/clitests.json

@@ -1,5 +1,5 @@
 {
- "spec_dir": "build/lib/test/unit",
+ "spec_dir": "build/lib-es5/test/unit",
 
  "helpers": [
  "clitests_helper.js"