feat(cat): implement multi-file reading with error handling

- Refactor to async readMultipleFiles() function
- Support reading multiple files via Promise.all
- Output concatenated file contents to stdout
- Add error handling with exit code 1 on failure
- Remove debug logging (argv, path)
- Fix markdown list formatting in README (bullets)

Author: Iswanna

implement-shell-tools/cat/README.md

@@ -6,11 +6,11 @@ Your task is to implement your own version of `cat`.
 
 It must act the same as `cat` would, if run from the directory containing this README.md file, for the following command lines:
 
-* `cat sample-files/1.txt`
-* `cat -n sample-files/1.txt`
-* `cat sample-files/*.txt`
-* `cat -n sample-files/*.txt`
-* `cat -b sample-files/3.txt`
+- `cat sample-files/1.txt`
+- `cat -n sample-files/1.txt`
+- `cat sample-files/*.txt`
+- `cat -n sample-files/*.txt`
+- `cat -b sample-files/3.txt`
 
 Matching any additional behaviours or flags are optional stretch goals.
 

implement-shell-tools/cat/cat.js

@@ -1,12 +1,19 @@
 import process from "node:process";
-import { promises as fs } from "node:fs";
+import { promises as fs, readFile } from "node:fs";
 
-const argv = process.argv.slice(2);
-console.log(argv);
+const filesToRead = process.argv.slice(2);
+console.log(filesToRead);
 
-const path = argv[0];
+async function readMultipleFiles() {
+  try {
+    const results = await Promise.all(
+      filesToRead.map((file) => fs.readFile(file, "utf-8")),
+    );
+    process.stdout.write(results.join(""));
+  } catch (err) {
+    console.error("Error reading multiple files:", err);
+    process.exitCode = 1;
+  }
+}
 
-console.log(path);
-
-const content = await fs.readFile(path, "utf-8");
-console.log(content.trim());
+readMultipleFiles();