feat(strings): add wordWrap*() fns

thi-ng · Jan 8, 2021 · 2a283c0 · 2a283c0
1 parent 86fa81a
commit 2a283c0
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diff --git a/packages/strings/src/index.ts b/packages/strings/src/index.ts
@@ -27,3 +27,4 @@ export * from "./truncate-left";
 export * from "./units";
 export * from "./uuid";
 export * from "./wrap";
+export * from "./word-wrap";
diff --git a/packages/strings/src/word-wrap.ts b/packages/strings/src/word-wrap.ts
@@ -0,0 +1,43 @@
+import { lengthAnsi } from "./ansi";
+
+export const wordWrap = (str: string, lineWidth?: number) =>
+    wordWrapLines(str, lineWidth).join("\n");
+
+export const wordWrapLines = (str: string, lineWidth = 80) => {
+    const res: string[] = [];
+    for (let line of str.split("\n")) {
+        if (!line.length) {
+            res.push("");
+            continue;
+        }
+        wordWrapLine(line, lineWidth, res);
+    }
+    return res;
+};
+
+export const wordWrapLine = (
+    line: string,
+    lineWidth = 80,
+    acc: string[] = []
+) => {
+    let ln = 0;
+    let curr: string[] = [];
+    for (let w of line.split(" ")) {
+        const l = lengthAnsi(w) + (ln > 0 ? 1 : 0);
+        if (ln + l <= lineWidth) {
+            curr.push(w, " ");
+            ln += l;
+        } else {
+            acc.push(trimLine(curr));
+            curr = [w, " "];
+            ln = l;
+        }
+    }
+    ln && acc.push(trimLine(curr));
+    return acc;
+};
+
+const trimLine = (x: string[]) => {
+    /^\s+$/.test(x[x.length - 1]) && x.pop();
+    return x.join("");
+};