Allow configuring 'currentVersion'

Rather than always obtaining the 'currentVersion' of the project from
an environment variable, it can now be passed in via a CLI flag
instead.

Additionally, the validation for the version has been improved. It will
now throw if the current version isn't a valid SemVer version, as our
update logic depends upon it being valid. We also now ensure that the
error message for a messing version is only printed when it was
strictly required (it wasn't used for non-RC updates), and that the
script terminates at that point.

Closes #10

Author: Gudahtt

src/cli.js

@@ -2,6 +2,7 @@
 /* eslint-disable node/no-process-exit */
 
 const { promises: fs, constants: fsConstants } = require('fs');
+const semver = require('semver');
 const yargs = require('yargs/yargs');
 const { hideBin } = require('yargs/helpers');
 
@@ -38,6 +39,12 @@ async function main() {
             description: 'The changelog file path',
             type: 'string',
           })
+          .option('currentVersion', {
+            default: npmPackageVersion,
+            description:
+              'The current version of the project that the changelog belongs to.',
+            type: 'string',
+          })
           .epilog(updateEpilog),
     )
     .strict()
@@ -47,19 +54,26 @@ async function main() {
       `Utilities for validating and updating "Keep a Changelog" formatted changelogs.\nUsage: $0 [command] [options]`,
     );
 
-  if (!npmPackageVersion) {
+  const {
+    currentVersion,
+    file: changelogFilename,
+    rc: isReleaseCandidate,
+  } = argv;
+
+  if (isReleaseCandidate && !currentVersion) {
     console.error(
-      `npm package version not found. Please run this as an npm script from a project with the 'version' field set.`,
+      `Version not found. Please set the --currentVersion flag, or run this as an npm script from a project with the 'version' field set.`,
     );
+    process.exit(1);
+  } else if (currentVersion && semver.valid(currentVersion) === null) {
+    console.error(`Current version is not valid SemVer: '${currentVersion}'`);
+    process.exit(1);
   } else if (!npmPackageRepositoryUrl) {
     console.error(
       `npm package repository URL not found. Please run this as an npm script from a project with the 'repository' field set.`,
     );
   }
 
-  const isReleaseCandidate = argv.rc;
-  const changelogFilename = argv.file;
-
   try {
     // eslint-disable-next-line no-bitwise
     await fs.access(changelogFilename, fsConstants.F_OK | fsConstants.W_OK);
@@ -78,7 +92,7 @@ async function main() {
 
   const newChangelogContent = await updateChangelog({
     changelogContent,
-    currentVersion: npmPackageVersion,
+    currentVersion,
     repoUrl: npmPackageRepositoryUrl,
     isReleaseCandidate,
   });

src/updateChangelog.js

@@ -100,7 +100,8 @@ function getAllLoggedPrNumbers(changelog) {
  * PRs that are already included in the changelog are omitted.
  * @param {Object} options
  * @param {string} options.changelogContent - The current changelog
- * @param {Version} options.currentVersion - The current version
+ * @param {Version} [options.currentVersion] - The current version. Required if
+ *   `isReleaseCandidate` is set, but optional otherwise.
  * @param {string} options.repoUrl - The GitHub repository URL for the current
  *   project.
  * @param {boolean} options.isReleaseCandidate - Denotes whether the current
@@ -115,6 +116,11 @@ async function updateChangelog({
   repoUrl,
   isReleaseCandidate,
 }) {
+  if (isReleaseCandidate && !currentVersion) {
+    throw new Error(
+      `A version must be specified if 'isReleaseCandidate' is set.`,
+    );
+  }
   const changelog = parseChangelog({ changelogContent, repoUrl });
 
   // Ensure we have all tags on remote