Respect home path boundaries in pwd (#13)

Author: aiirvizionz

src/pwd.mjs

@@ -82,5 +82,7 @@ export function locate(cwd = process.cwd()) {
 
 // Collapse $HOME to `~` for tidy display.
 export function tilde(p, home) {
-  return home && p.startsWith(home) ? "~" + p.slice(home.length) : p;
+  if (!home || p === home) return home ? "~" : p;
+  const relative = p.slice(home.length);
+  return p.startsWith(home) && relative.startsWith(path.sep) ? "~" + relative : p;
 }

test/pwd.test.mjs

@@ -0,0 +1,25 @@
+import assert from "node:assert/strict";
+import path from "node:path";
+import test from "node:test";
+
+import { tilde } from "../src/pwd.mjs";
+
+test("tilde shortens the home directory itself", () => {
+  const home = path.join("C:", "Users", "mosh");
+
+  assert.equal(tilde(home, home), "~");
+});
+
+test("tilde shortens paths inside home", () => {
+  const home = path.join("C:", "Users", "mosh");
+  const project = path.join(home, "repo");
+
+  assert.equal(tilde(project, home), `~${path.sep}repo`);
+});
+
+test("tilde does not shorten sibling paths with the same prefix", () => {
+  const home = path.join("C:", "Users", "mosh");
+  const sibling = path.join("C:", "Users", "mosh-other", "repo");
+
+  assert.equal(tilde(sibling, home), sibling);
+});