+ trim, trimStart, and trimEnd methods

CHANGELOG.md

@@ -4,16 +4,22 @@ The format is based on [EZEZ Changelog](https://ezez.dev/changelog/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [UNRELEASED]
+- (nothing yet)
+
+## [4.0.0] - 2024-05-16
 ### Breaking
-- `replaceDeep` will not mutate anything by default — previously it was wrongly documented as always mutating,
-but it was not mutating objects. Mutating behavior can be enabled and additionally controlled by defining if instances
-properties are allowed to be mutated.
-- `serialize` to avoid excessive calls to serializer functions - now they are only called with non-plain objects or unknown data types, this breaks some rare use cases
+- `replaceDeep` will not mutate anything by default anymore — previously it was wrongly documented as always mutating,
+but it was not mutating objects. Mutating behavior can now be enabled and additionally controlled by defining if
+instances properties are allowed to be mutated.
+- [`serialize`] to avoid excessive calls to serializer functions - they are now only called with non-plain objects or
+unknown data types, this breaks some rare use cases
 ### Changed
-- `serialize` custom serializers now allow things like `Date` (that defines .toJSON) to be supported as the user would expect
+- `serialize` custom serializers now allow things like `Date` (that defines .toJSON) to be supported as the user would
+expect
 ### Added
 - `replaceDeepByFn` method for more granular control over replacing values. `replaceDeep` is a simplified wrapper over
 the new function
+- `trim`, `trimStart`, and `trimEnd` methods
 ### Dev
 - upgraded some jsdocs
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ezez/utils",
-  "version": "3.0.0+",
+  "version": "4.0.0",
   "repository": "https://github.com/dzek69/bottom-line.git",
   "author": "Jacek Nowacki @dzek69 <git-public@dzek.eu>",
   "license": "MIT",

src/index.ts

@@ -52,6 +52,9 @@ export * from "./stripPrefix.js";
 export * from "./stripSuffix.js";
 export * from "./throttle.js";
 export * from "./toggle.js";
+export * from "./trim.js";
+export * from "./trimEnd.js";
+export * from "./trimStart.js";
 export * from "./truthy.js";
 export * from "./unique.js";
 export * from "./wait.js";

src/trim.spec.ts

@@ -0,0 +1,22 @@
+import { trim } from "./trim";
+
+describe("trim", () => {
+    it("should trim single character from both sides of the string", async () => {
+        must(trim("aaacataaa", "a")).equal("cat");
+        must(trim("abacteria", "a")).equal("bacteri");
+        must(trim("abc", "a")).equal("bc");
+        must(trim("abc", "c")).equal("ab");
+        must(trim("aajjja", "a")).equal("jjj");
+    });
+
+    it("should trim multiple characters as a whole", async () => {
+        must(trim("abopopab", "ab")).equal("opop");
+        must(trim("atitleb", "ab")).equal("atitleb");
+        must(trim("abtitleab", "ab")).equal("title");
+    });
+
+    it("can trim into empty string", async () => {
+        must(trim("abc", "abc")).equal("");
+        must(trim("a", "a")).equal("");
+    });
+});

src/trim.ts

@@ -0,0 +1,23 @@
+import { trimStart } from "./trimStart.js";
+import { trimEnd } from "./trimEnd.js";
+
+/**
+ * Removes given characters from both sides of the string.
+ * If you want to remove from one side of the string see {@link trimStart} and {@link trimEnd}.
+ *
+ * @param source - Source string.
+ * @param characters - Characters to remove, taken as a whole.
+ *
+ * @example
+ * trim("abcb", "ab"); // "cb"
+ * trim("!aaa!", "!"); // "aaa"
+ * trim("!aaa!!!", "!"); // "aaa"
+ * trim("!aaa!!!", "!!!"); // "!aaa"
+ */
+const trim = (source: string, characters: string) => {
+    return trimStart(trimEnd(source, characters), characters);
+};
+
+export {
+    trim,
+};

src/trimEnd.spec.ts

@@ -0,0 +1,20 @@
+import { trimEnd } from "./trimEnd";
+
+describe("trimEnd", () => {
+    it("should trim single character from the end of the string", async () => {
+        must(trimEnd("abc?", "?")).equal("abc");
+        must(trimEnd("a? b?c???", "?")).equal("a? b?c");
+    });
+
+    it("should trim multiple characters as a whole", async () => {
+        must(trimEnd("abc", "bc")).equal("a");
+
+        must(trimEnd("abcc", "bc")).equal("abcc");
+        must(trimEnd("abcb", "bc")).equal("abcb");
+    });
+
+    it("can trim into empty string", async () => {
+        must(trimEnd("abc", "abc")).equal("");
+        must(trimEnd("a", "a")).equal("");
+    });
+});

src/trimEnd.ts

@@ -0,0 +1,22 @@
+/**
+ * Removes given characters from the end of the string.
+ * See also: {@link trim} and {@link trimStart}.
+ *
+ * @param source - Source string.
+ * @param characters - Characters to remove, taken as a whole.
+ *
+ * @example
+ * trimEnd("abcxzyz", "yz"); // "abcxz"
+ * trimEnd("!aaa!!", "!"); // "!aaa"
+ */
+const trimEnd = (source: string, characters: string) => {
+    let s = source;
+    while (s.endsWith(characters)) {
+        s = s.slice(0, -characters.length);
+    }
+    return s;
+};
+
+export {
+    trimEnd,
+};

src/trimStart.spec.ts

@@ -0,0 +1,20 @@
+import { trimStart } from "./trimStart";
+
+describe("trimStart", () => {
+    it("should trim single character from the start of the string", async () => {
+        must(trimStart("?abc", "?")).equal("abc");
+        must(trimStart("aaabc", "a")).equal("bc");
+    });
+
+    it("should trim multiple characters as a whole", async () => {
+        must(trimStart("abc", "ab")).equal("c");
+
+        must(trimStart("aabcc", "ab")).equal("aabcc");
+        must(trimStart("babcb", "ab")).equal("babcb");
+    });
+
+    it("should trim into empty string if needed", async () => {
+        must(trimStart("abc", "abc")).equal("");
+        must(trimStart("aaa", "a")).equal("");
+    });
+});

src/trimStart.ts

@@ -0,0 +1,22 @@
+/**
+ * Removes given characters from the start of the string.
+ * See also: {@link trim} and {@link trimEnd}.
+ *
+ * @param source - Source string.
+ * @param characters - Characters to remove, taken as a whole.
+ *
+ * @example
+ * trimStart("abbcb", "ab"); // "bcb"
+ * trimStart("!!aaa!", "!"); // "aaa!"
+ */
+const trimStart = (source: string, characters: string) => {
+    let s = source;
+    while (s.startsWith(characters)) {
+        s = s.slice(characters.length);
+    }
+    return s;
+};
+
+export {
+    trimStart,
+};