Merge function for objects

.npmignore

@@ -1,3 +1,6 @@
+*.md
+*.test.js
+*.test.ts
 .all-contributorsrc
 .babelrc.js
 .coverage
@@ -9,14 +12,12 @@
 .npmignore
 .prettierignore
 .prettierrc
-*.test.js
-*.test.ts
 addExtensions.js
 compile.js
 document.js
 ignore.js
+normalizeLineEndings.js
 package-lock.json
 readme.js
 regenerate.js
 rollup.config.js
-*.md

.prettierignore

@@ -1,4 +1,3 @@
 .coverage
 index.cjs.js
 index.umd.js
-.coverage

README.md

@@ -3770,6 +3770,34 @@ mapValues(); // ⇒ TODO
 TODO: List questions that may this function answers.
 TODO-END -->
 
+#### merge
+
+Merges two objects deeply.
+
+##### Type signature
+
+```
+(a: object, b: object) => object
+```
+
+##### Examples
+
+```javascript
+merge({ a: 1, b: 3 }, {}); // ⇒ { a: 1, b: 3 }
+```
+
+```javascript
+merge({ a: 1, b: 3 }, { b: 7 }); // ⇒ { a: 1, b: 7 }
+```
+
+```javascript
+merge({ a: 1, b: 3 }, { b: { d: 8 } }); // ⇒ { a: 1, b: { d: 8 } }
+```
+
+```javascript
+merge({ a: 1, b: { c: 3 } }, { b: { d: 8 } }); // ⇒ { a: 1, b: { c: 3, d: 8 } }
+```
+
 #### none
 
 <!-- TODO-START

ignore.js

@@ -20,6 +20,7 @@ const ignoredFiles = [
   "index.umd.js",
   "jest.config.js",
   "LICENSE",
+  "normalizeLineEndings.js",
   "package-lock.json",
   "package.json",
   "readme.js",

normalizeLineEndings.js

@@ -0,0 +1,72 @@
+/* eslint-env node */
+// eslint-disable console
+import { promises } from "fs";
+import path from "path";
+import os from "os";
+import pQueue from "p-queue";
+
+const CONCURRENCY = Math.max(1, os.cpus().length - 1);
+
+const { default: PQueue } = pQueue;
+
+import ignored from "./ignore.js";
+
+const [, ignoredDirectories] = ignored;
+
+const {
+  readFile: readFileAsync,
+  writeFile: writeFileAsync,
+  readdir: readDirectoryAsync
+} = promises;
+
+const [, , cwd = process.cwd()] = process.argv;
+const root = cwd;
+
+const main = async cwd => {
+  console.log(`Normalizing files in ${cwd}...`);
+
+  const entries = await readDirectoryAsync(cwd, { withFileTypes: true });
+
+  const files = entries.filter(x => x.isFile()).map(x => x.name);
+
+  const directories = entries
+    .filter(x => x.isDirectory())
+    .map(x => x.name)
+    .filter(x => !ignoredDirectories.includes(x));
+
+  for (const directory of directories) {
+    await main(path.join(cwd, directory));
+  }
+
+  const processFile = async file => {
+    const filePath = path.join(cwd, file);
+    const relativeFilePath = path.relative(root, filePath);
+
+    try {
+      console.log(`Normalizing ${relativeFilePath}...`);
+
+      const contents = await readFileAsync(filePath, "utf-8");
+
+      const normalized = contents
+        .split("\n")
+        .map(x => x.trimEnd())
+        .join("\n");
+
+      await writeFileAsync(filePath, normalized, "utf-8");
+    } catch (error) {
+      console.error(error);
+
+      process.exit(1);
+    }
+  };
+
+  const queue = new PQueue({ concurrency: CONCURRENCY });
+
+  for (const file of files) {
+    queue.add(() => processFile(file));
+  }
+
+  await queue.onIdle();
+};
+
+main(cwd);

object/README.md

@@ -544,6 +544,34 @@ mapValues(); // ⇒ TODO
 TODO: List questions that may this function answers.
 TODO-END -->
 
+# merge
+
+Merges two objects deeply.
+
+## Type signature
+
+```
+(a: object, b: object) => object
+```
+
+## Examples
+
+```javascript
+merge({ a: 1, b: 3 }, {}); // ⇒ { a: 1, b: 3 }
+```
+
+```javascript
+merge({ a: 1, b: 3 }, { b: 7 }); // ⇒ { a: 1, b: 7 }
+```
+
+```javascript
+merge({ a: 1, b: 3 }, { b: { d: 8 } }); // ⇒ { a: 1, b: { d: 8 } }
+```
+
+```javascript
+merge({ a: 1, b: { c: 3 } }, { b: { d: 8 } }); // ⇒ { a: 1, b: { c: 3, d: 8 } }
+```
+
 # none
 
 <!-- TODO-START

object/apply.ts

@@ -1,5 +1,5 @@
 import entries from "./entries";
 import fromEntries from "./fromEntries";
 
-export default fs => (...xs) =>
+export default (fs: { (...xs: any[]): any }[]) => (...xs: any[]) =>
   fromEntries(entries(fs).map(([key, value]) => [key, value(...xs)]));

object/entries.js

@@ -1,2 +1 @@
-export default Object.entries ||
-  (object => Object.keys(object).map(key => [key, object[key]]));
+export default Object.entries;

object/entries.ts

@@ -1,2 +1 @@
-export default Object.entries ||
-  (object => Object.keys(object).map(key => [key, object[key]]));
+export default Object.entries;

object/fromEntries.js

@@ -1,6 +1,4 @@
-export default Object.fromEntries ||
-  (keyValuePairs =>
-    keyValuePairs.reduce(
-      (acc, [key, value]) => ({ ...acc, [key]: value }),
-      {}
-    ));
+const fromEntries = keyValuePairs =>
+  keyValuePairs.reduce((acc, [key, value]) => ({ ...acc, [key]: value }), {});
+
+export default Object.fromEntries || fromEntries;

object/fromEntries.ts

@@ -1,6 +1,4 @@
-export default Object.fromEntries ||
-  (keyValuePairs =>
-    keyValuePairs.reduce(
-      (acc, [key, value]) => ({ ...acc, [key]: value }),
-      {}
-    ));
+const fromEntries = (keyValuePairs: [string, any][]): object =>
+  keyValuePairs.reduce((acc, [key, value]) => ({ ...acc, [key]: value }), {});
+
+export default Object.fromEntries || fromEntries;

object/index.js

@@ -19,6 +19,7 @@ import map from "./map.js";
 import mapEntries from "./mapEntries.js";
 import mapKeys from "./mapKeys.js";
 import mapValues from "./mapValues.js";
+import merge from "./merge.js";
 import none from "./none.js";
 import sort from "./sort.js";
 
@@ -44,6 +45,7 @@ export {
   mapEntries,
   mapKeys,
   mapValues,
+  merge,
   none,
   sort
 };
@@ -70,6 +72,7 @@ export default {
   mapEntries,
   mapKeys,
   mapValues,
+  merge,
   none,
   sort
 };

object/index.ts

@@ -19,6 +19,7 @@ import map from "./map";
 import mapEntries from "./mapEntries";
 import mapKeys from "./mapKeys";
 import mapValues from "./mapValues";
+import merge from "./merge";
 import none from "./none";
 import sort from "./sort";
 
@@ -44,6 +45,7 @@ export {
   mapEntries,
   mapKeys,
   mapValues,
+  merge,
   none,
   sort
 };
@@ -70,6 +72,7 @@ export default {
   mapEntries,
   mapKeys,
   mapValues,
+  merge,
   none,
   sort
 };

object/map.ts

@@ -1,4 +1,6 @@
 import fromEntries from "./fromEntries";
 import mapEntries from "./mapEntries";
 
-export default f => xs => fromEntries(mapEntries(f)(xs));
+export default (f: (value: any, key: string, context: object) => any) => (
+  xs: object
+) => fromEntries(mapEntries(f)(xs));

object/mapEntries.ts

@@ -1,4 +1,6 @@
 import entries from "./entries";
 
-export default f => xs =>
+export default (f: (value: any, key: string, context: object) => any) => (
+  xs: object
+): [string, any][] =>
   entries(xs).map(([key, value]) => [key, f(value, key, xs)]);

object/merge.js

@@ -0,0 +1,15 @@
+import isObject from "../is/object.js";
+import map from "./map.js";
+
+const isNonNullishObject = x => x !== undefined && x !== null && isObject(x);
+
+const merge = (a, b) => ({
+  ...a,
+  ...map((value, key) =>
+    isNonNullishObject(value) && isNonNullishObject(a[key])
+      ? merge(a[key], value)
+      : value
+  )(b)
+});
+
+export default merge;

object/merge.md

@@ -0,0 +1,27 @@
+# merge
+
+Merges two objects deeply.
+
+## Type signature
+
+```
+(a: object, b: object) => object
+```
+
+## Examples
+
+```javascript
+merge({ a: 1, b: 3 }, {}); // ⇒ { a: 1, b: 3 }
+```
+
+```javascript
+merge({ a: 1, b: 3 }, { b: 7 }); // ⇒ { a: 1, b: 7 }
+```
+
+```javascript
+merge({ a: 1, b: 3 }, { b: { d: 8 } }); // ⇒ { a: 1, b: { d: 8 } }
+```
+
+```javascript
+merge({ a: 1, b: { c: 3 } }, { b: { d: 8 } }); // ⇒ { a: 1, b: { c: 3, d: 8 } }
+```