Don't extract errors in CI

Removes `--extract-errors` argument from CI build script command.
Instead, the author is expected to run `yarn extract-errors` locally
or manually edit the error code map.

The lint rule should be sufficient to catch unminified errors, but
as an extra precaution, I added a post-build step that greps the
production bundles. The post-build step works even if someone disables
the lint rule for a specific line or file.

.circleci/config.yml

@@ -124,7 +124,7 @@ jobs:
       - *run_yarn
       - run: ./scripts/circleci/add_build_info_json.sh
       - run: ./scripts/circleci/update_package_versions.sh
-      - run: ./scripts/circleci/build.sh
+      - run: yarn build
       - run: cp ./scripts/rollup/results.json ./build/bundle-sizes.json
       - run: ./scripts/circleci/upload_build.sh
       - run: ./scripts/circleci/pack_and_store_artifact.sh
@@ -145,7 +145,6 @@ jobs:
             - bundle-sizes.json
 
   sizebot:
-    build:
     docker: *docker
     environment: *environment
     steps:
@@ -155,6 +154,17 @@ jobs:
       - *run_yarn
       - run: node ./scripts/tasks/danger
 
+  lint_build:
+    docker: *docker
+    environment: *environment
+    steps:
+      - checkout
+      - attach_workspace: *attach_workspace
+      - *restore_yarn_cache
+      - *run_yarn
+      - run: yarn lint-build
+      - run: scripts/circleci/check_minified_errors.sh
+
   test_build:
     docker: *docker
     environment: *environment
@@ -222,6 +232,9 @@ workflows:
       - sizebot:
           requires:
             - build
+      - lint_build:
+          requires:
+            - build
       - test_build:
           requires:
             - build

scripts/circleci/check_minified_errors.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+# Ensure errors are minified in production
+
+OUT=$(git --no-pager grep -n --untracked --no-exclude-standard 'FIXME (minify-errors-in-prod)' -- './build/*')
+
+if [ "$OUT" != "" ]; then
+  echo "$OUT";
+  echo -e "\n";
+  echo "Detected an unminified error message in the production build. User-facing errors message must have a corresponding error code in scripts/error-codes/codes.json."
+  exit 1
+fi
+
+exit 0

scripts/error-codes/__tests__/__snapshots__/transform-error-messages.js.snap

@@ -4,7 +4,7 @@ exports[`error transform should correctly transform invariants that are not in t
 "import _ReactError from 'shared/ReactError';
 
 import invariant from 'shared/invariant';
-(function () {
+/*FIXME (minify-errors-in-prod): Unminified error message in production build!*/(function () {
   if (!condition) {
     throw _ReactError(\`This is not a real error message.\`);
   }
@@ -15,7 +15,7 @@ exports[`error transform should handle escaped characters 1`] = `
 "import _ReactError from 'shared/ReactError';
 
 import invariant from 'shared/invariant';
-(function () {
+/*FIXME (minify-errors-in-prod): Unminified error message in production build!*/(function () {
   if (!condition) {
     throw _ReactError(\`What's up?\`);
   }

scripts/error-codes/transform-error-messages.js

@@ -60,19 +60,37 @@ module.exports = function(babel) {
             ])
           );
 
+          if (noMinify) {
+            // Error minification is disabled for this build.
+            //
+            // Outputs:
+            //   if (!condition) {
+            //     throw ReactError(`A ${adj} message that contains ${noun}`);
+            //   }
+            path.replaceWith(
+              t.ifStatement(
+                t.unaryExpression('!', condition),
+                t.blockStatement([devThrow])
+              )
+            );
+            return;
+          }
+
           // Avoid caching because we write it as we go.
           const existingErrorMap = JSON.parse(
             fs.readFileSync(__dirname + '/codes.json', 'utf-8')
           );
           const errorMap = invertObject(existingErrorMap);
 
           let prodErrorId = errorMap[errorMsgLiteral];
-          if (prodErrorId === undefined || noMinify) {
-            // There is no error code for this message. We use a lint rule to
-            // enforce that messages can be minified, so assume this is
-            // intentional and exit gracefully.
+
+          if (prodErrorId === undefined) {
+            // There is no error code for this message. Add an inline comment
+            // that flags this as an unminified error. This allows the build
+            // to proceed, while also allowing a post-build linter to detect it.
             //
             // Outputs:
+            //   /* FIXME (minify-errors-in-prod): Unminified error message in production build! */
             //   if (!condition) {
             //     throw ReactError(`A ${adj} message that contains ${noun}`);
             //   }
@@ -82,6 +100,10 @@ module.exports = function(babel) {
                 t.blockStatement([devThrow])
               )
             );
+            path.addComment(
+              'leading',
+              'FIXME (minify-errors-in-prod): Unminified error message in production build!'
+            );
             return;
           }
           prodErrorId = parseInt(prodErrorId, 10);