Major refactor (#18381)

src/utilities/get-string-width.js

@@ -0,0 +1,61 @@
+import emojiRegex from "emoji-regex";
+import {
+  // @ts-expect-error -- Private
+  _isFullWidth as isFullWidth,
+  // @ts-expect-error -- Private
+  _isWide as isWide,
+} from "get-east-asian-width";
+import narrowEmojis from "./narrow-emojis.evaluate.js";
+
+const notAsciiRegex = /[^\x20-\x7F]/u;
+const narrowEmojisSet = new Set(narrowEmojis);
+
+// Similar to https://github.com/sindresorhus/string-width
+// We don't strip ansi, always treat ambiguous width characters as having narrow width.
+/**
+ * @param {string} text
+ * @returns {number}
+ */
+function getStringWidth(text) {
+  if (!text) {
+    return 0;
+  }
+
+  // shortcut to avoid needless string `RegExp`s, replacements, and allocations
+  if (!notAsciiRegex.test(text)) {
+    return text.length;
+  }
+
+  text = text.replace(emojiRegex(), (match) =>
+    narrowEmojisSet.has(match) ? " " : "  ",
+  );
+  let width = 0;
+
+  // Use `Intl.Segmenter` when we drop support for Node.js v14
+  // https://github.com/prettier/prettier/pull/14793#discussion_r1185840038
+  // https://github.com/sindresorhus/string-width/pull/47
+  for (const character of text) {
+    const codePoint = character.codePointAt(0);
+
+    // Ignore control characters
+    if (codePoint <= 0x1f || (codePoint >= 0x7f && codePoint <= 0x9f)) {
+      continue;
+    }
+
+    // Ignore combining characters
+    if (codePoint >= 0x300 && codePoint <= 0x36f) {
+      continue;
+    }
+
+    // Ignore Variation Selectors
+    if (codePoint >= 0xfe00 && codePoint <= 0xfe0f) {
+      continue;
+    }
+
+    width += isFullWidth(codePoint) || isWide(codePoint) ? 2 : 1;
+  }
+
+  return width;
+}
+
+export default getStringWidth;