feat: Add "latest" switch (#541)

README.md

@@ -23,14 +23,16 @@ Allowed version argument inputs:
 Options:
   -d, --debug             Enable debug logging
   -f, --force             Force downloading the latest release file
+  -a, --latest            List only the latest release (alias for --limit 1,
+                          disables limit)
   -l, --limit <number>    Limit output of releases
   -r, --raw               Output raw JSON
   -s, --source <url>      Use a custom releases source URL or path
   -t, --timeout <number>  Use a custom HTTP timeout
   -v, --version           output the version number
   --no-colors             Don't use colors for displaying
   --no-prereleases        Don't include Electron prereleases
-  -h, --help              output usage information
+  -h, --help              display help for command
 
 Commands:
   electron|e [version]    Get informations about an Electron release
@@ -42,6 +44,7 @@ Commands:
   v8|v [version]          Get informations about V8 releases
   zlib|z [version]        Get informations about zlib releases
   all|a                   Get informations about all releases
+  help [command]          display help for command
 ```
 
 ### Examples

spec/ElectronInfo.test.ts

@@ -155,5 +155,16 @@ describe('ElectronInfo', () => {
         tempDirectory: tempDirDownload,
       }).getDependencyReleases('chrome', 'all');
     });
+
+    it('Uses latest as alias for limit=1', async () => {
+      const result = await new ElectronInfo({
+        latest: true,
+        releasesUrl: mockUrl,
+        tempDirectory: tempDir,
+      }).getElectronReleases('all');
+
+      expect(result.length).toBe(1);
+      expect(result[0].version).toBe('8.0.0-nightly.20190820');
+    });
   });
 });

src/ElectronInfo.ts

@@ -36,8 +36,14 @@ export interface Options {
   electronPrereleases?: boolean;
   /** Force downloading the latest release file. Default: `false`. */
   forceUpdate?: boolean;
+  /**
+   * Include only the latest release. Alias for `limit=1`. Disables `limit`.
+   * Default: `false`.
+   */
+  latest?: boolean;
   /**
    * Limit output of releases. Everything below 1 will be treated as no limit.
+   * Disables `latest`.
    * Default: 0.
    */
   limit?: number;
@@ -59,6 +65,7 @@ const defaultOptions: Required<Options> = {
   debug: false,
   electronPrereleases: true,
   forceUpdate: false,
+  latest: false,
   limit: 0,
   releasesUrl: 'https://raw.githubusercontent.com/electron/releases/master/lite.json',
   tempDirectory: '',
@@ -99,7 +106,7 @@ export class ElectronInfo {
   async getAllReleases(formatted?: boolean, colored?: boolean): Promise<RawReleaseInfo[] | string> {
     this.logger.log('Getting all releases:', {colored, formatted});
     const allReleases = await this.fileService.getReleases();
-    const limitedReleases = this.limitReleases(allReleases, this.options.limit);
+    const limitedReleases = this.limitReleases(allReleases);
     return formatted ? this.formatReleases(limitedReleases, colored) : limitedReleases;
   }
 
@@ -123,7 +130,7 @@ export class ElectronInfo {
       release => release.deps && dependencyVersions.includes(release.deps[dependency])
     );
 
-    const limitedReleases = this.limitReleases(filteredReleases, this.options.limit);
+    const limitedReleases = this.limitReleases(filteredReleases);
     return formatted ? this.formatDependencyReleases(limitedReleases, colored) : limitedReleases;
   }
 
@@ -140,7 +147,7 @@ export class ElectronInfo {
     const electronVersions = await this.getVersions(allReleases, 'electron', version);
     const filteredReleases = allReleases.filter(release => electronVersions.includes(release.version));
 
-    const limitedReleases = this.limitReleases(filteredReleases, this.options.limit);
+    const limitedReleases = this.limitReleases(filteredReleases);
     return formatted ? this.formatReleases(limitedReleases, colored) : limitedReleases;
   }
 
@@ -255,7 +262,8 @@ export class ElectronInfo {
     return dependencyVersions;
   }
 
-  private limitReleases(releases: RawReleaseInfo[], limit?: number): RawReleaseInfo[] {
+  private limitReleases(releases: RawReleaseInfo[]): RawReleaseInfo[] {
+    const limit = this.options.limit || (this.options.latest ? 1 : undefined);
     if (limit) {
       const slicedArray = releases.slice(0, limit);
       this.logger.log('Limiting found versions', {

src/cli.ts

@@ -28,6 +28,7 @@ Allowed version argument inputs:
   )
   .option('-d, --debug', 'Enable debug logging')
   .option('-f, --force', 'Force downloading the latest release file')
+  .option('-a, --latest', 'List only the latest release (alias for --limit 1, disables limit)')
   .option('-l, --limit <number>', 'Limit output of releases')
   .option('-r, --raw', 'Output raw JSON')
   .option('-s, --source <url>', 'Use a custom releases source URL or path')