Restore experimental build script's ability to auto download latest build (#20717)

scripts/release/download-experimental-build.js

@@ -18,15 +18,16 @@ const printSummary = require('./download-experimental-build-commands/print-summa
 const run = async () => {
   try {
     addDefaultParamValue('-r', '--releaseChannel', 'experimental');
+    addDefaultParamValue(
+      null,
+      '--build',
+      await getLatestMasterBuildNumber(true)
+    );
 
     const params = await parseParams();
     params.cwd = join(__dirname, '..', '..');
     params.packages = await getPublicPackages(true);
 
-    if (!params.build) {
-      params.build = await getLatestMasterBuildNumber(true);
-    }
-
     await checkEnvironmentVariables(params);
     await downloadBuildArtifacts(params);
 

scripts/release/utils.js

@@ -17,18 +17,18 @@ const logger = createLogger({
   storagePath: join(__dirname, '.progress-estimator'),
 });
 
-const addDefaultParamValue = (shortName, longName, defaultValue) => {
+const addDefaultParamValue = (optionalShortName, longName, defaultValue) => {
   let found = false;
   for (let i = 0; i < process.argv.length; i++) {
     const current = process.argv[i];
-    if (current === shortName || current.startsWith(`${longName}=`)) {
+    if (current === optionalShortName || current.startsWith(`${longName}=`)) {
       found = true;
       break;
     }
   }
 
   if (!found) {
-    process.argv.push(shortName, defaultValue);
+    process.argv.push(`${longName}=${defaultValue}`);
   }
 };