Merge pull request #14 from nrabinowitz/docker-build

Build C library with docker

.travis.yml

@@ -1,17 +1,30 @@
 language: node_js
+
 node_js:
   - '6'
   - '8'
   - '10'
+
+sudo: required
+
+services:
+  - docker
+
+before_install:
+  - yarn init-docker
+
 before_script:
-  - yarn run dist-test
+  - yarn build-emscripten
+  - yarn dist-test
+
 script:
   - yarn lint
-  - yarn run test-es6
-  - yarn run test-dist
-  - yarn run test-parity
-  - yarn run prettier && git diff --exit-code
+  - yarn test-es6
+  - yarn test-dist
+  - yarn test-parity
+  - yarn prettier && git diff --exit-code
   - yarn cover
+
 after_success:
   - npm install -g coveralls
   - cat coverage/lcov.info | coveralls

README.md

@@ -103,24 +103,15 @@ When making code changes that may affect performance, please run benchmarks agai
 
 ### Transpiling the C Source
 
-You need to have emscripten's `emcc` in your `$PATH`. I highly recommend [the portable install](http://kripken.github.io/emscripten-site/docs/getting_started/downloads.html) as easiest to update and maintain.
+The core library is transpiled using [emscripten](http://kripken.github.io/emscripten-site). The easiest way to build from source locally is by using Docker. Make sure Docker is installed, then:
 
-Once you finished the installation, run the following command to check the precompiled package versions:
+    yarn init-docker
+    yarn run build-emscripten
 
-    emsdk list
+The build script uses the `H3_VERSION` file to determine the version of the core library to build.
 
 NOTE: The current `h3-js` is built with `emscripten-1.37.40`. Earlier or later versions MAY NOT WORK (emscripten does not follow semver, so patch updates may include breaking changes).
 
-Note that you'll need to add the emscripten PATH and env variables to your current terminal (unless you add this to your `.bash_profile`):
-
-    source /path/to/emsdk_portable/emsdk_env.sh
-
-Then simply:
-
-    yarn run build-emscripten
-
-The build script automatically uses the `package.json` version as the version of `libh3` to build, so these versions are completely in sync with the upstream C code.
-
 ## Contributing
 
 Pull requests and [Github issues](https://github.com/uber/h3-js/issues) are welcome. Please include tests for new work, and keep the library test coverage at 100%. Please note that the purpose of this module is to expose the API of the [H3 Core library](https://github.com/uber/h3), so we will rarely accept new features that are not part of that API. New proposed feature work is more appropriate in the core C library or in a new JS library that depends on `h3-js`.

package.json

@@ -33,7 +33,8 @@
     "dist-test": "yarn run dist && buble -i test -o dist/test",
     "benchmarks": "yarn run dist-test && node dist/test/benchmarks.js",
     "prepublish": "yarn run dist",
-    "build-emscripten": "./.build-emscripten.sh",
+    "init-docker": "docker run -dit --name emscripten -v $(pwd):/src trzeci/emscripten:sdk-tag-1.37.40-64bit bash",
+    "build-emscripten": "docker exec -it emscripten bash .build-emscripten.sh",
     "cover": "istanbul cover -x out/*.js -- test/index.js",
     "prettier": "prettier --write --single-quote --no-bracket-spacing --print-width=100 'lib/**/*.js' 'build/**/*.js' 'test/**/*.js'"
   },