[Danger] Improve the lookup for previous -> current build to also include the environment

Author: orta

dangerfile.js

@@ -11,7 +11,11 @@ const {markdown, danger} = require('danger');
 const fetch = require('node-fetch');
 
 const {generateResultsArray} = require('./scripts/rollup/stats');
-const currentBuildResults = require('./scripts/rollup/results.json');
+const {readFileSync} = require('fs');
+
+const currentBuildResults = JSON.parse(
+  readFileSync('./scripts/rollup/results.json')
+);
 
 /**
  * Generates a Markdown table

scripts/circleci/build.sh

@@ -7,7 +7,7 @@ set -e
 # accurate.
 curl -o scripts/rollup/results.json http://react.zpao.com/builds/master/latest/results.json
 
-yarn build
+yarn build --extract-errors
 # Note: since we run the full build including extracting error codes,
 # it is important that we *don't* reset the change to `scripts/error-codes/codes.json`.
 # When production bundle tests run later, it needs to be available.

scripts/rollup/stats.js

@@ -46,7 +46,9 @@ function generateResultsArray(current, prevResults) {
   return current.bundleSizes
     .map(result => {
       const prev = prevResults.bundleSizes.filter(
-        res => res.filename === result.filename
+        res =>
+          res.filename === result.filename &&
+          res.bundleType === result.bundleType
       )[0];
       if (result === prev) {
         // We didn't rebuild this bundle.