initial version

tests/character.test.ts

@@ -0,0 +1,39 @@
+import {
+  assertEquals,
+  assertThrows,
+} from "https://deno.land/std@0.224.0/assert/mod.ts";
+
+import { getCharacterWidth } from "../mod.ts";
+
+Deno.test("getCharacterWidth ASCII", () => {
+  assertEquals(getCharacterWidth("a"), 1);
+  assertEquals(getCharacterWidth("A"), 1);
+  assertEquals(getCharacterWidth("1"), 1);
+  assertEquals(getCharacterWidth("@"), 1);
+  assertEquals(getCharacterWidth(" "), 1);
+
+  assertThrows(() => getCharacterWidth(""));
+  assertThrows(() => getCharacterWidth("ab"));
+});
+
+Deno.test("getCharacterWidth CJK", () => {
+  assertEquals(getCharacterWidth("你"), 2);
+  assertEquals(getCharacterWidth("好"), 2);
+  assertEquals(getCharacterWidth("吗"), 2);
+
+  assertEquals(getCharacterWidth("ガ"), 2);
+  assertEquals(getCharacterWidth("ギ"), 2);
+  assertEquals(getCharacterWidth("グ"), 2);
+  assertEquals(getCharacterWidth("ソ"), 2);
+
+  assertThrows(() => getCharacterWidth("？"));
+  assertThrows(() => getCharacterWidth("！"));
+  assertThrows(() => getCharacterWidth("你好"));
+  assertThrows(() => getCharacterWidth("ヨスガノ"));
+});
+
+Deno.test("getCharacterWidth previously faulty cases", () => {
+  assertEquals(getCharacterWidth("𤲶"), 2);
+
+  assertThrows(() => getCharacterWidth("𤲶"[0]));
+});