Patch libh3 to include a document undefined check

CHANGELOG.md

@@ -3,6 +3,8 @@
 All notable changes to this project will be documented in this file. This library adheres to a versioning policy described in [the README](./README.md#versioning). The public API of this library consists of the functions exported in [h3core.js](./lib/h3core.js).
 
 ## [Unreleased]
+### Fixed
+- Patch libh3 bundles to check for `typeof document != "undefined"` before accessing `document`. This allows h3-js to be used in a Web Worker and React Native
 
 ## [4.0.1] - 2022-09-19
 ### Changed

scripts/update-emscripten.sh

@@ -57,7 +57,11 @@ emcc -O3 -I ../include *.c -DH3_HAVE_VLA --memory-init-file 0 \
     "$@"
 
 for file in *.js ; do
-  cat ../../../../build/pre.js "$file" > ../../../../out/"$file"
+  # Patch libh3 bundle to contain a fix to allow h3-js to be imported in a web worker and react-native
+  # See #117 and #163 for more details.
+  cat ../../../../build/pre.js "$file" \
+  | sed 's/if(document.currentScript)/if(typeof document!=="undefined" \&\& document.currentScript)/g' \
+  > ../../../../out/"$file"
 done
 
 popd

test/index.js

@@ -17,3 +17,4 @@
 import './h3core.spec';
 import './errors.spec';
 import './test-parity';
+import './test-build';

test/test-build.js

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2018-2019 Uber Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import test from 'tape';
+import fs from 'fs';
+import path from 'path';
+
+const LIBH3_PATH = path.join(__dirname, '../out/libh3.js');
+
+const ORIGINAL_DOCUMENT_REGEX = /if\(document.currentScript\)/;
+const PATCHED_DOCUMENT_REGEX = /if\(typeof document!=="undefined" && document.currentScript\)/;
+
+test('validateLIBH3HasDocumentUndefinedFix', assert => {
+    // Validate that the bundle does not contain a bug that prevents h3-js to be imported into webworkers and react native.
+    // Problem was fixed in a later version of emscripten however there are significant performance regressions when upgrading.
+    // See #163 and #117 for more details.
+    const fileContents = fs.readFileSync(LIBH3_PATH, {encoding: 'utf8', flag: 'r'});
+    assert.doesNotMatch(fileContents, ORIGINAL_DOCUMENT_REGEX, 'bundle was not patched');
+    assert.match(fileContents, PATCHED_DOCUMENT_REGEX, 'bundle was not patched');
+    assert.end();
+});