Refactor for easier testing

following example from tj/commander.js#1565 (comment)

bin/cli.js

@@ -0,0 +1,25 @@
+#!/usr/bin/env node
+
+const command = require("../lib/command");
+const program = command.makeProgram();
+
+function main() {
+  try {
+    program.parse(process.argv);
+  } catch (err) {
+    if (err instanceof Error) {
+      //   if (program.opts().debug) {
+      //     console.error(`${err.stack}`);
+      //   }
+      //   if (err.message !== util.suppressTerminateExceptionMessage) {
+      console.log(`caught exception with message ${err.message}`);
+      //   }
+    } else {
+      throw err;
+    }
+    // Recommended practice for node is set exitcode not force exit
+    process.exitCode = 7; // Exit with code 7 if an exception occurred
+  }
+}
+
+main().then(() => {});

lib/command.js

@@ -0,0 +1,86 @@
+const { Command, Option } = require("commander");
+const audiomothUtils = require("audiomoth-utils");
+
+function makeProgram() {
+  const program = new Command();
+
+  program
+    .description(
+      "Expand an AudioMoth T.WAV recording (a recording with amplitude thresholding or frequency triggering applied)"
+    ) // TODO use addCommand to handle the subcommands
+    .arguments("<subcommand> <inputFile>")
+    .option(
+      "-d, --destination [outputPath]",
+      "output directory to write expansions. If omitted, dump expanded files in the same folder as inputFile."
+    )
+    .option(
+      "--prefix [prefix]",
+      "optional string (not including '_') to prefix to expanded filenames that will be created."
+    )
+    .addOption(
+      new Option(
+        "--max-file-duration [seconds]",
+        "max duration of expanded file to write, in seconds"
+      )
+        .argParser(parseInt)
+        .default(5)
+    )
+    .option("--generate-silent-files", "generate silent files", false)
+    .option(
+      "--align-to-second-transitions",
+      "align to second transitions",
+      false
+    )
+    .action((subcommand, inputFile, options) => {
+      const {
+        destination,
+        prefix,
+        maxFileDuration,
+        generateSilentFiles,
+        alignToSecondTransitions,
+      } = options;
+
+      // Determine expansionType based on command
+      let expansionType;
+      switch (subcommand) {
+        case "expand-duration":
+          expansionType = "DURATION";
+          break;
+        case "expand-event":
+          expansionType = "EVENT";
+          break;
+        default:
+          console.error("Invalid subcommand");
+          process.exit(9);
+      }
+
+      // Call the expand function with the provided arguments and options
+      const result = audiomothUtils.expand(
+        inputFile,
+        destination, // optional
+        prefix, // optional
+        expansionType,
+        maxFileDuration,
+        generateSilentFiles,
+        alignToSecondTransitions
+      );
+
+      if (result?.success) {
+        console.log("Expansion completed successfully.");
+        process.exit(0); // Exit with code 0 if success is true
+      } else {
+        console.error("Expansion failed:", result?.error);
+        process.exit(1); // Exit with code 1 if success is false
+      }
+    });
+  return program;
+}
+
+function fab(args) {
+  makeProgram().parse(args, { from: "user" });
+}
+
+module.exports = {
+  makeProgram: makeProgram,
+  fab: fab,
+};

package.json

@@ -3,17 +3,19 @@
   "version": "1.0.0",
   "description": "A thin CLI wrapper over AudioMoth-Utils",
   "bin": {
-    "hello-world": "./bin/audiomoth-utils.js"
+    "audiomoth-utils": "./bin/cli.js"
   },
   "scripts": {
-    "start": "node ./bin/audiomoth-utils.js",
-    "build": "pkg . --targets node14-linux-x64,node14-win-x64 --out-path  dist"
+    "start": "node ./bin/cli.js",
+    "build": "pkg . --targets node14-linux-x64,node14-win-x64 --out-path dist",
+    "test": "jest"
   },
   "dependencies": {
     "audiomoth-utils": "1.5.0",
     "commander": "^12.1.0"
   },
   "devDependencies": {
+    "jest": "^29.7.0",
     "pkg": "^5.8.1"
   }
 }

test/command.test.js

@@ -0,0 +1,38 @@
+const command = require("../lib/command");
+
+const audiomothUtils = require("audiomoth-utils");
+
+jest.mock("audiomoth-utils", () => ({
+  expand: jest.fn(),
+}));
+
+describe("audiomoth-utils CLI", () => {
+  beforeEach(() => {
+    audiomothUtils.expand.mockClear();
+    audiomothUtils.expand.mockReturnValue({ success: true });
+    // Mock console.log and console.error
+    console.log = jest.fn();
+    console.error = jest.fn();
+    // Mock process.exit
+    process.exit = jest.fn();
+  });
+
+  test("calling with no arguments uses default values", () => {
+    command.fab(["expand-duration", "input.wav"]);
+
+    expect(audiomothUtils.expand).toHaveBeenCalledWith(
+      "input.wav",
+      undefined,
+      undefined,
+      "DURATION",
+      5,
+      false,
+      false
+    );
+
+    expect(console.log).toHaveBeenCalledWith(
+      "Expansion completed successfully."
+    );
+    expect(process.exit).toHaveBeenCalledWith(0);
+  });
+});