build: Add validation script for peer dependencies versions (#522)

## Details

This PR adds a validation step in the CI to ensure the validity of the peer-dependencies versions. This would prevent in the future issues where `peerDependencies` and `devDependencies` gets out of sync.

<img width="1107" alt="screen shot 2018-07-19 at 6 55 06 am" src="https://user-images.githubusercontent.com/2567083/42946895-ecbede6c-8b20-11e8-914d-d3a0f05eb4b1.png">

**🗒 Note:** Since lerna doesn't update the `peerDependencies` when doing a version bump and push automatically the generated commit, the next major version bump will cause a CI breakage on the branch we will be releasing. #523

## Does this PR introduce a breaking change?

* [ ] Yes
* [X] No

.circleci/config.yml

@@ -22,6 +22,10 @@ jobs:
             - packages/*/node_modules
           key: yarn-v4-{{ checksum "yarn.lock" }}
 
+      - run:
+          name: Validation package versions
+          command: node ./scripts/tasks/version-check.js
+
       - run:
           name: Run Linting
           command: yarn lint

package.json

@@ -40,10 +40,12 @@
     "commitizen": "~2.9.6",
     "conventional-changelog-cli": "~1.3.5",
     "cz-conventional-changelog": "~2.1.0",
+    "glob": "^7.1.2",
     "husky": "^1.0.0-rc.4",
     "jest": "~23.1.0",
     "lerna": "2.9.0",
     "prettier": "~1.10.2",
+    "semver": "^5.5.0",
     "ts-jest": "~22.0.4",
     "tslint": "~5.9.1",
     "typescript": "2.7.2"

scripts/tasks/version-check.js

@@ -0,0 +1,40 @@
+'use strict';
+
+const path = require('path');
+const glob = require('glob');
+const semver = require('semver');
+
+const PACKAGES_DIR = path.resolve(__dirname, '../../packages');
+const PACKAGES = glob.sync('*/package.json', {
+    absolute: true,
+    cwd: PACKAGES_DIR,
+});
+
+let areVersionsInSync = true;
+for (const location of PACKAGES) {
+    const {
+        name,
+        peerDependencies = {},
+        devDependencies = {},
+    } = require(location);
+
+    for (const dep of Object.keys(peerDependencies)) {
+        if (
+            devDependencies.hasOwnProperty(dep) &&
+            !semver.satisfies(devDependencies[dep], peerDependencies[dep])
+        ) {
+            const error = [
+                `Peer and dev versions of ${dep} in ${name} are out of sync.`,
+                `(Expected: ${peerDependencies[dep]}, Actual: ${devDependencies[dep]})`,
+                `Please update the peer dependency version.`,
+            ].join(' ');
+
+            console.error(error);
+            areVersionsInSync = false;
+        }
+    }
+}
+
+if (!areVersionsInSync) {
+    process.exit(1);
+}