test(tui): cover ZWSP, ZWJ, ZWNJ, and BOM in label rendering

Author: CoderLuii

packages/opencode/src/util/locale.test.ts

@@ -0,0 +1,110 @@
+import { describe, it, expect } from "bun:test"
+import { truncate, truncateMiddle } from "./locale"
+
+describe("truncate", () => {
+  it("returns the string unchanged when its rendered width fits", () => {
+    const input = "hello"
+    expect(truncate(input, 10)).toBe(input)
+    expect(truncate(input, 5)).toBe(input)
+  })
+
+  it("does not truncate a U+200B-prefixed string whose rendered width equals the limit", () => {
+    const input = "\u200BSisyphus"
+    expect(Bun.stringWidth(input)).toBe(8)
+    expect(truncate(input, 8)).toBe(input)
+  })
+
+  it("truncates a U+200B-prefixed string whose rendered width exceeds the limit at the visible boundary", () => {
+    const input = "\u200BSisyphus: Ultraworker"
+    const result = truncate(input, 10)
+    expect(result.endsWith("…")).toBe(true)
+    const body = result.slice(0, -1)
+    expect(Bun.stringWidth(body) + 1).toBeLessThanOrEqual(10)
+    expect(Bun.stringWidth(result)).toBeLessThanOrEqual(10)
+    expect(result).toBe("\u200BSisyphus:…")
+  })
+
+  it("truncates plain ASCII to display width ending in ellipsis", () => {
+    const result = truncate("Sisyphus: Ultraworker", 10)
+    expect(result.endsWith("…")).toBe(true)
+    expect(Bun.stringWidth(result)).toBe(10)
+    expect(result).toBe("Sisyphus:…")
+  })
+
+  it("handles all zero-width codepoint variants (U+200C, U+200D, U+FEFF)", () => {
+    const zwnj = "\u200CSisyphus: Ultraworker"
+    const zwj = "\u200DSisyphus: Ultraworker"
+    const bom = "\uFEFFSisyphus: Ultraworker"
+    const resultZwnj = truncate(zwnj, 10)
+    const resultZwj = truncate(zwj, 10)
+    const resultBom = truncate(bom, 10)
+    expect(resultZwnj.endsWith("…")).toBe(true)
+    expect(resultZwj.endsWith("…")).toBe(true)
+    expect(resultBom.endsWith("…")).toBe(true)
+    expect(Bun.stringWidth(resultZwnj)).toBeLessThanOrEqual(10)
+    expect(Bun.stringWidth(resultZwj)).toBeLessThanOrEqual(10)
+    expect(Bun.stringWidth(resultBom)).toBeLessThanOrEqual(10)
+    expect(resultZwnj).toBe("\u200CSisyphus:…")
+    expect(resultZwj).toBe("\u200DSisyphus:…")
+    expect(resultBom).toBe("\uFEFFSisyphus:…")
+  })
+
+  it("truncates mixed strings containing emoji, ZWSP, and ASCII correctly", () => {
+    const input = "🔥\u200BSisyphus: Ultraworker"
+    expect(Bun.stringWidth("🔥")).toBe(2)
+    const result = truncate(input, 10)
+    expect(result.endsWith("…")).toBe(true)
+    expect(Bun.stringWidth(result)).toBeLessThanOrEqual(10)
+    expect(result).toBe("🔥\u200BSisyphu…")
+  })
+})
+
+describe("truncateMiddle", () => {
+  it("returns the string unchanged when its rendered width is <= maxLength", () => {
+    const input = "hello world"
+    expect(truncateMiddle(input, 20)).toBe(input)
+    expect(truncateMiddle(input, 11)).toBe(input)
+  })
+
+  it("does not truncate a U+200B-prefixed string at exact width", () => {
+    const input = "\u200BSisyphus"
+    expect(Bun.stringWidth(input)).toBe(8)
+    expect(truncateMiddle(input, 8)).toBe(input)
+  })
+
+  it("truncates a long ZWSP-bearing string in the middle with correct widths", () => {
+    const input = "\u200BSisyphus: Ultraworker helps you"
+    const maxLength = 15
+    const result = truncateMiddle(input, maxLength)
+    expect(result.includes("…")).toBe(true)
+    expect(Bun.stringWidth(result)).toBeLessThanOrEqual(maxLength)
+    const ellipsisIndex = result.indexOf("…")
+    const startOut = result.slice(0, ellipsisIndex)
+    const endOut = result.slice(ellipsisIndex + 1)
+    const budget = maxLength - 1
+    const keepStart = Math.ceil(budget / 2)
+    const keepEnd = Math.floor(budget / 2)
+    expect(Bun.stringWidth(startOut)).toBeLessThanOrEqual(keepStart)
+    expect(Bun.stringWidth(endOut)).toBeLessThanOrEqual(keepEnd)
+    expect(result.startsWith("\u200B")).toBe(true)
+    expect(result.endsWith("u")).toBe(true)
+    expect(result).toBe("\u200BSisyphu…lps you")
+  })
+
+  it("uses a default maxLength of 35", () => {
+    const short = "a".repeat(35)
+    expect(truncateMiddle(short)).toBe(short)
+    const long = "a".repeat(50)
+    const result = truncateMiddle(long)
+    expect(result.includes("…")).toBe(true)
+    expect(Bun.stringWidth(result)).toBeLessThanOrEqual(35)
+  })
+
+  it("truncates plain ASCII with unchanged behavior", () => {
+    const input = "abcdefghijklmnopqrstuvwxyz"
+    const result = truncateMiddle(input, 10)
+    expect(result.includes("…")).toBe(true)
+    expect(Bun.stringWidth(result)).toBeLessThanOrEqual(10)
+    expect(result).toBe("abcde…wxyz")
+  })
+})