build: add a script to fix order of deps keys in package.json files

Add a new step to `bin/fix-monorepo.js` to ensure that all
public packages list deps in the following order, starting
after `publishConfig` or `license` field:

    1. `peerDependencies`
    2. `dependencies
    3. `devDependencies`

Signed-off-by: Miroslav Bajtoš <[email protected]>

bin/fix-monorepo.js

@@ -10,14 +10,19 @@
  */
 'use strict';
 
+const path = require('path');
+
 const syncDevDeps = require('./sync-dev-deps');
 const updateMonorepo = require('./update-monorepo-file');
 
 const {
+  isJsonEqual,
+  loadLernaRepo,
   runMain,
   updatePackageDeps,
   updatePackageJson,
   updateTsProjectRefs,
+  writeJsonSync,
 } = require('../packages/monorepo');
 
 async function fixMonorepo() {
@@ -31,6 +36,57 @@ async function fixMonorepo() {
   await updateMonorepo();
   // Ensure TypeScript project references are up to date
   await updateTsProjectRefs();
+  // Ensure consistent order of keys in package.json
+  await updateOrderOfPackageJsonFields();
 }
 
 runMain(module, fixMonorepo);
+
+async function updateOrderOfPackageJsonFields() {
+  const {packages} = await loadLernaRepo();
+  for (const pkg of packages.filter(p => !p.private)) {
+    const manifest = pkg.toJSON();
+
+    // Keys to update in the desired order,
+    // filtered to those present in `package.json` only.
+    const depKeys = [
+      'peerDependencies',
+      'dependencies',
+      'devDependencies',
+    ].filter(k => k in manifest);
+
+    // Get all top-level keys like "name", "version", "dependencies"
+    let keys = Object.keys(manifest);
+    // Remove "*dependencies"
+    keys = keys.filter(k => !depKeys.includes(k));
+
+    // Find the position of "publishConfig" (if present) or "license"
+    let ix = keys.indexOf('publishConfig');
+    if (ix === -1) {
+      ix = keys.indexOf('license');
+      if (ix === -1) {
+        const relPath = path.relative(pkg.rootPath, pkg.manifestLocation);
+        throw new Error(
+          `Fatal error: ${relPath} is missing required "license" field.`,
+        );
+      }
+    }
+
+    // Insert back "*dependencies" after "publishConfig" or "license"
+    keys.splice(
+      ix + 1, // index at which to start changing the array.
+      0, // number of elements to remove
+      ...depKeys, // elements to insert
+    );
+
+    // Build a new manifest with the keys in the correct order
+    const updated = {};
+    for (const k of keys) {
+      updated[k] = manifest[k];
+    }
+
+    if (!isJsonEqual(updated, manifest)) {
+      writeJsonSync(pkg.manifestLocation, updated);
+    }
+  }
+}