feat(closes #178): add cli help and version

BREAKING CHANGE: updated node version range will cause installation fail for Node versions less 12.20.0

cli.js

@@ -1,25 +1,40 @@
 #!/usr/bin/env node
 
-const { mergeFiles } = require("./src/mergeFiles.js");
+const { Command } = require('commander')
+const pkg = require('./package.json')
+const { mergeFiles } = require('./src/mergeFiles.js')
 
-const [, , destFilePath, ...srcFilePathsOrGlobPatterns] = process.argv;
+function getProgram() {
+  const program = new Command()
+  program.version(pkg.version)
+  program.description(
+    pkg.description +
+      '\n\n' +
+      'Example (combines a.xml and b.xml into target.xml):\n  jrm target.xml a.xml b.xml' +
+      '\n\n' +
+      'Example (glob patterns to match input files):\n  jrm ./results/combined.xml "./results/units/*.xml" "./results/e2e/*.xml"'
+  )
+  program.arguments('<destination> <sources...>')
+  return program
+}
 
-(async () => {
-    try {
-        let processedFileCount = 0;
-        await mergeFiles(destFilePath, srcFilePathsOrGlobPatterns, {
-            onFileMatched: () => {
-                ++processedFileCount;
-            },
-        });
-        console.log(`Done. ${processedFileCount} files processed.`);
-        if (processedFileCount === 0) {
-            console.log(
-                "Provided input file patterns did not matched any file."
-            );
-        }
-    } catch (err) {
-        console.error(err);
-        process.exitCode = 1;
+const program = getProgram()
+program.action(async function (destination, sources) {
+  const destFilePath = destination
+  const srcFilePathsOrGlobPatterns = sources
+
+  let processedFileCount = 0
+  await mergeFiles(destFilePath, srcFilePathsOrGlobPatterns, {
+    onFileMatched: () => {
+      ++processedFileCount
     }
-})();
+  })
+  process.stdout.write(`Done. ${processedFileCount} files processed.\n`)
+  if (processedFileCount === 0) {
+    process.stdout.write(`Provided input file patterns did not matched any file.\n`)
+  }
+})
+program.parseAsync().catch((e) => {
+  console.error(e)
+  process.exitCode = 1
+})

package.json

@@ -21,8 +21,9 @@
     "typings": "tsc index.js --declaration --allowJs --emitDeclarationOnly --outDir typings"
   },
   "dependencies": {
-    "fast-glob": "3.2.11",
-    "xmlbuilder2": "3.0.2"
+    "commander": "~9.4.0",
+    "fast-glob": "~3.2.11",
+    "xmlbuilder2": "~3.0.2"
   },
   "repository": {
     "type": "git",
@@ -45,14 +46,14 @@
   },
   "homepage": "https://github.com/bhovhannes/junit-report-merger#readme",
   "devDependencies": {
-    "@evilmartians/lefthook": "1.0.5",
     "@bhovhannes/shared-config": "0.0.1",
+    "@evilmartians/lefthook": "1.0.5",
     "@jest/globals": "28.1.3",
     "jest": "28.1.3",
     "prettier": "2.7.1",
     "typescript": "4.7.4"
   },
   "engines": {
-    "node": ">=12"
+    "node": "^12.20.0 || >=14"
   }
 }