Added position to the truncate function

CHANGELOG.md

@@ -1,5 +1,11 @@
 # deverything
 
+## 0.47.2
+
+### Patch Changes
+
+- added position to truncate
+
 ## 0.47.1
 
 ### Patch Changes

package.json

@@ -1,6 +1,6 @@
 {
   "name": "deverything",
-  "version": "0.47.1",
+  "version": "0.47.2",
   "description": "Everything you need for Dev",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",

src/helpers/truncate.test.ts

@@ -2,14 +2,65 @@ import { describe, expect, test } from "@jest/globals";
 import { truncate } from "./truncate";
 
 describe("truncate", () => {
-  test("works", async () => {
+  test("basic functionality", async () => {
     expect(truncate("asd", -Infinity)).toBe("asd");
     expect(truncate("asd", Infinity)).toBe("asd");
     expect(truncate("asd", -1)).toBe("asd");
     expect(truncate("", 0)).toBe("");
     expect(truncate("", 1)).toBe("");
     expect(truncate("1", 1)).toBe("1");
-    expect(truncate("1 ", 1)).toBe("1...");
-    expect(truncate("😴😄😃⛔🎠🚓🚇", 4)).toBe("😴😄😃⛔...");
+    expect(truncate("12345", 4)).toBe("1...");
+    expect(truncate("😴😄😃⛔🎠🚓🚇", 4)).toBe("😴...");
+  });
+  test("truncation at the start", () => {
+    expect(
+      truncate("Hello, world!", 8, {
+        position: "start",
+      })
+    ).toBe("...orld!");
+    expect(
+      truncate("😴😄😃⛔🎠🚓🚇", 6, {
+        position: "start",
+      })
+    ).toBe("...🎠🚓🚇");
+  });
+
+  test("truncation in the middle", () => {
+    expect(
+      truncate("Hello, world!", 11, {
+        position: "middle",
+      })
+    ).toBe("Hell...rld!");
+    expect(
+      truncate("😴😄😃⛔🎠🚓🚇", 5, {
+        position: "middle",
+      })
+    ).toBe("😴...🚇");
+  });
+
+  test("truncation at the end", () => {
+    expect(
+      truncate("Hello, world!", 10, {
+        position: "end",
+      })
+    ).toBe("Hello, ...");
+    expect(
+      truncate("😴😄😃⛔🎠🚓🚇", 5, {
+        position: "end",
+      })
+    ).toBe("😴😄...");
+  });
+
+  test("custom ellipsis", () => {
+    const originalUrl =
+      "https://very-long-url.com/path?query=string&anotherParam=value";
+    const expectedUrl =
+      "https://very-long-url.com[...]string&anotherParam=value";
+    expect(
+      truncate(originalUrl, 55, {
+        ellipsis: "[...]",
+        position: "middle",
+      })
+    ).toBe(expectedUrl);
   });
 });

src/helpers/truncate.ts

@@ -1,11 +1,40 @@
 import { isPositiveInt } from "../validators/isNumber";
 
-export const truncate = (arg: string, limit: number, ellipsis = "...") => {
+export const truncate = (
+  arg: string,
+  limit: number,
+  {
+    ellipsis,
+    position,
+  }: { ellipsis?: string; position?: "start" | "middle" | "end" } = {}
+) => {
+  if (!ellipsis) ellipsis = "...";
+  if (!position) position = "end";
+
   if (!isPositiveInt(limit)) return arg;
 
   const argArray = [...arg]; // convert string to array, emoji and unicode safe
 
+  const ellipsisLength = ellipsis.length;
+
   if (argArray.length <= limit) return arg;
 
-  return argArray.slice(0, limit).join("") + ellipsis;
+  switch (position) {
+    case "start":
+      const startSliceLength = limit - ellipsisLength;
+      return ellipsis + argArray.slice(-startSliceLength).join("");
+    case "middle": {
+      const startSliceLength = Math.ceil((limit - ellipsisLength) / 2);
+      const endSliceStart =
+        argArray.length - Math.floor((limit - ellipsisLength) / 2);
+      return (
+        argArray.slice(0, startSliceLength).join("") +
+        ellipsis +
+        argArray.slice(endSliceStart).join("")
+      );
+    }
+    case "end":
+    default:
+      return argArray.slice(0, limit - ellipsisLength).join("") + ellipsis;
+  }
 };