Sort printed mappings and fields in update check CLI (#176493)

## Summary

Close https://github.com/elastic/kibana/issues/168927

Adds a new utility to pretty print and sort JS objects and use this in
the mappings update check CLI for both fields and mappings.

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

packages/kbn-check-mappings-update-cli/src/compatibility/current_mappings.ts

@@ -10,13 +10,14 @@ import Fsp from 'fs/promises';
 import Path from 'path';
 
 import type { SavedObjectsTypeMappingDefinitions } from '@kbn/core-saved-objects-base-server-internal';
+import { prettyPrintAndSortKeys } from '@kbn/utils';
 
-export const CURRENT_MAPPINGS_FILE = Path.resolve(__dirname, '../../current_mappings.json');
+export const CURRENT_MAPPINGS_FILE_PATH = Path.resolve(__dirname, '../../current_mappings.json');
 
 export async function readCurrentMappings(): Promise<SavedObjectsTypeMappingDefinitions> {
   let currentMappingsJson;
   try {
-    currentMappingsJson = await Fsp.readFile(CURRENT_MAPPINGS_FILE, 'utf8');
+    currentMappingsJson = await Fsp.readFile(CURRENT_MAPPINGS_FILE_PATH, 'utf8');
   } catch (error) {
     if (error.code === 'ENOENT') {
       return {};
@@ -28,6 +29,10 @@ export async function readCurrentMappings(): Promise<SavedObjectsTypeMappingDefi
   return JSON.parse(currentMappingsJson);
 }
 
-export async function updateCurrentMappings(newMappings: SavedObjectsTypeMappingDefinitions) {
-  await Fsp.writeFile(CURRENT_MAPPINGS_FILE, JSON.stringify(newMappings, null, 2) + '\n', 'utf8');
+export async function writeCurrentMappings(newMappings: SavedObjectsTypeMappingDefinitions) {
+  await Fsp.writeFile(
+    CURRENT_MAPPINGS_FILE_PATH,
+    prettyPrintAndSortKeys(newMappings) + '\n',
+    'utf8'
+  );
 }

packages/kbn-check-mappings-update-cli/src/compatibility/run_mappings_compatibility_check.ts

@@ -13,7 +13,7 @@ import { createTestEsCluster } from '@kbn/test';
 import { extractMappingsFromPlugins } from './extract_mappings_from_plugins';
 import { checkAdditiveOnlyChange } from './check_additive_only_change';
 import { checkIncompatibleMappings } from './check_incompatible_mappings';
-import { readCurrentMappings, updateCurrentMappings } from './current_mappings';
+import { readCurrentMappings, writeCurrentMappings } from './current_mappings';
 
 export const runMappingsCompatibilityChecks = async ({
   fix,
@@ -78,7 +78,7 @@ export const runMappingsCompatibilityChecks = async ({
   }
 
   if (fix) {
-    await updateCurrentMappings(extractedMappings);
+    await writeCurrentMappings(extractedMappings);
     log.warning(
       `Updated extracted mappings in current_mappings.json file, please commit the changes if desired.`
     );

packages/kbn-check-mappings-update-cli/src/mappings_additions/current_fields.ts

@@ -9,6 +9,7 @@
 import { readFile, writeFile } from 'fs/promises';
 import Path from 'path';
 import { FieldListMap } from '@kbn/core-saved-objects-base-server-internal';
+import { prettyPrintAndSortKeys } from '@kbn/utils';
 
 const CURRENT_FIELDS_FILE_PATH = Path.resolve(__dirname, '../../current_fields.json');
 
@@ -25,5 +26,5 @@ export const readCurrentFields = async (): Promise<FieldListMap> => {
 };
 
 export const writeCurrentFields = async (fieldMap: FieldListMap) => {
-  await writeFile(CURRENT_FIELDS_FILE_PATH, JSON.stringify(fieldMap, null, 2) + '\n', 'utf-8');
+  await writeFile(CURRENT_FIELDS_FILE_PATH, prettyPrintAndSortKeys(fieldMap) + '\n', 'utf-8');
 };

packages/kbn-check-mappings-update-cli/tsconfig.json

@@ -28,5 +28,6 @@
     "@kbn/safer-lodash-set",
     "@kbn/tooling-log",
     "@kbn/core-saved-objects-server",
+    "@kbn/utils",
   ]
 }

packages/kbn-utils/index.ts

@@ -5,6 +5,6 @@
  * in compliance with, at your election, the Elastic License 2.0 or the Server
  * Side Public License, v 1.
  */
-
+export * from './src/json';
 export * from './src/path';
 export * from './src/streams';

packages/kbn-utils/src/json/index.test.ts

@@ -0,0 +1,85 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { prettyPrintAndSortKeys } from '.';
+
+describe('prettyPrintAndSortKeys', () => {
+  it('pretty prints JSON and consistently sorts the keys', () => {
+    const object1 = {
+      zap: { z: 1, b: 2 },
+      foo: 'foo',
+      bar: 'bar',
+    };
+    const object2 = {
+      foo: 'foo',
+      zap: { z: 1, b: 2 },
+      bar: 'bar',
+    };
+    expect(prettyPrintAndSortKeys(object1)).toMatchInlineSnapshot(`
+      "{
+        \\"bar\\": \\"bar\\",
+        \\"foo\\": \\"foo\\",
+        \\"zap\\": {
+          \\"b\\": 2,
+          \\"z\\": 1
+        }
+      }"
+    `);
+
+    expect(prettyPrintAndSortKeys(object1)).toEqual(prettyPrintAndSortKeys(object2));
+  });
+
+  it('pretty prints and sorts nested objects with arrays', () => {
+    const object = {
+      zap: {
+        a: {
+          b: 1,
+          a: 2,
+        },
+      },
+      foo: 'foo',
+      bar: 'bar',
+      baz: [
+        {
+          c: 2,
+          b: 1,
+        },
+        {
+          c: {
+            b: 1,
+            a: 2,
+          },
+        },
+      ],
+    };
+    expect(prettyPrintAndSortKeys(object)).toMatchInlineSnapshot(`
+      "{
+        \\"bar\\": \\"bar\\",
+        \\"baz\\": [
+          {
+            \\"b\\": 1,
+            \\"c\\": 2
+          },
+          {
+            \\"c\\": {
+              \\"a\\": 2,
+              \\"b\\": 1
+            }
+          }
+        ],
+        \\"foo\\": \\"foo\\",
+        \\"zap\\": {
+          \\"a\\": {
+            \\"a\\": 2,
+            \\"b\\": 1
+          }
+        }
+      }"
+    `);
+  });
+});

packages/kbn-utils/src/json/index.ts

@@ -0,0 +1,20 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+/**
+ * Given a JS object, will return a JSON.stringified result with consistently
+ * sorted keys.
+ */
+export function prettyPrintAndSortKeys(object: object): string {
+  const keys = new Set<string>();
+  JSON.stringify(object, (key, value) => {
+    keys.add(key);
+    return value;
+  });
+  return JSON.stringify(object, Array.from(keys).sort(), 2);
+}