feat(wc): add optional flags for line, word, and byte counting

Author: jakr-s

implement-shell-tools/wc/wc.js

@@ -1,14 +1,22 @@
 import { program } from "commander";
 import * as fs from "node:fs/promises";
 
-//*** TODO ***
-// * Format results
-// * Add optional flags
-
 program
   .name("wc")
   .description("word, line and byte count")
-  .argument("<paths...>", "The file path(s) to process");
+  .argument("<paths...>", "The file path(s) to process.")
+  .option(
+    "-l, --lines",
+    "The number of lines in each input file is written to the standard output.",
+  )
+  .option(
+    "-w, --words",
+    "The number of words in each input file is written to the standard output.",
+  )
+  .option(
+    "-c --bytes",
+    "The number of bytes in each input file is written to the standard output.",
+  );
 
 program.parse();
 
@@ -19,7 +27,6 @@ try {
   for (const filePath of filePaths) {
     const file = await fs.open(filePath);
     const stats = await fs.stat(filePath);
-
     const count = { lines: 0, words: 0, bytes: stats.size };
 
     try {
@@ -30,7 +37,6 @@ try {
     } finally {
       await file.close();
     }
-
     results[filePath] = count;
   }
 
@@ -44,7 +50,13 @@ try {
     results["total"] = total;
   }
 
-  console.table(results);
+  const options = program.opts();
+  const noOptionsProvided = !Object.keys(options).length;
+  const selectedOptionKeys = [...Object.keys(options)];
+
+  noOptionsProvided
+    ? console.table(results)
+    : console.table(results, selectedOptionKeys);
 } catch (err) {
   console.error(err.message);
 }