Added the --unstable flag to the ti sdk list command

lib/commands/sdk.js

@@ -116,6 +116,10 @@ SdkSubcommands.list = {
 				releases: {
 					abbr: 'r',
 					desc: 'retrieve and print all releases'
+				},
+				unstable: {
+					abbr: 'u',
+					desc: 'retrieve and print all unstable release candidate (rc) and beta releases'
 				}
 			},
 			options: {
@@ -143,7 +147,7 @@ async function list(logger, config, cli) {
 	const os = cli.env.os.name;
 
 	const [ releases, branches, branchBuilds ] = (await Promise.allSettled([
-		cli.argv.releases && getReleases(os),
+		(cli.argv.releases || cli.argv.unstable) && getReleases(os, cli.argv.unstable),
 		cli.argv.branches && getBranches(),
 		cli.argv.branch && getBranchBuilds(cli.argv.branch, os)
 	])).map(r => {
@@ -558,7 +562,7 @@ async function install(logger, config, cli) {
 	let downloadedFile = null;
 	let file           = null;
 	let url            = null;
-	const releases     = await getReleases(osName);
+	const releases     = await getReleases(osName, true);
 
 	// step 0: make sure the install location exists
 
@@ -1291,18 +1295,19 @@ async function uninstall(logger, config, cli) {
 /**
  * Retrieves the list of releases.
  * @param {String} os - The name of the OS (osx, linux, win32)
+ * @param {Boolean} [unstable] - When `true`, returns beta and rc releases along with ga releases.
  * @returns {Promise<Release[]>}
  */
-async function getReleases(os) {
+async function getReleases(os, unstable) {
 	const releaseRE = /^(\d+)\.(\d+)\.(\d+)\.(\w+)$/;
 	const releaseTypes = [ 'beta', 'rc', 'ga' ];
 
 	return (await Promise.allSettled([
-		got('https://downloads.titaniumsdk.com/registry/beta.json', { responseType: 'json' }).then(res => ({ type: 'beta', releases: res.body })),
-		got('https://downloads.titaniumsdk.com/registry/rc.json', { responseType: 'json' }).then(res => ({ type: 'rc', releases: res.body })),
+		unstable && got('https://downloads.titaniumsdk.com/registry/beta.json', { responseType: 'json' }).then(res => ({ type: 'beta', releases: res.body })),
+		unstable && got('https://downloads.titaniumsdk.com/registry/rc.json', { responseType: 'json' }).then(res => ({ type: 'rc', releases: res.body })),
 		got('https://downloads.titaniumsdk.com/registry/ga.json', { responseType: 'json' }).then(res => ({ type: 'ga', releases: res.body }))
 	])).flatMap(r => {
-		return r.status === 'fulfilled' ? r.value.releases.map(rel => {
+		return r.status === 'fulfilled' && r.value ? r.value.releases.map(rel => {
 			rel.type = r.value.type;
 			return rel;
 		}) : [];