fix: failed command usage string is missing arg descriptions and optional args

lib/command.ts

@@ -312,7 +312,7 @@ export class CommandInstance {
     // if this is the case, we should show the root usage instructions
     // rather than the usage instructions for the nested default command:
     if (isDefaultCommand)
-      innerYargs.getInternalMethods().getUsageInstance().unfreeze();
+      innerYargs.getInternalMethods().getUsageInstance().unfreeze(true);
     if (this.shouldUpdateUsage(innerYargs)) {
       innerYargs
         .getInternalMethods()

lib/usage.ts

@@ -707,22 +707,31 @@ export function usage(yargs: YargsInstance, shim: PlatformShim) {
       descriptions,
     });
   };
-  self.unfreeze = function unfreeze() {
+  self.unfreeze = function unfreeze(defaultCommand = false) {
     const frozen = frozens.pop();
     // In the case of running a defaultCommand, we reset
     // usage early to ensure we receive the top level instructions.
     // unfreezing again should just be a noop:
     if (!frozen) return;
-    ({
-      failMessage,
-      failureOutput,
-      usages,
-      usageDisabled,
-      epilogs,
-      examples,
-      commands,
-      descriptions,
-    } = frozen);
+    // Addresses: https://github.com/yargs/yargs/issues/2030
+    if (defaultCommand) {
+      descriptions = {...frozen.descriptions, ...descriptions};
+      commands = [...frozen.commands, ...commands];
+      usages = [...frozen.usages, ...usages];
+      examples = [...frozen.examples, ...examples];
+      epilogs = [...frozen.epilogs, ...epilogs];
+    } else {
+      ({
+        failMessage,
+        failureOutput,
+        usages,
+        usageDisabled,
+        epilogs,
+        examples,
+        commands,
+        descriptions,
+      } = frozen);
+    }
   };
 
   return self;
@@ -759,7 +768,7 @@ export interface UsageInstance {
   showHelpOnFail(enabled?: boolean | string, message?: string): UsageInstance;
   showVersion(level?: 'error' | 'log' | ((message: string) => void)): void;
   stringifiedValues(values?: any[], separator?: string): string;
-  unfreeze(): void;
+  unfreeze(defaultCommand?: boolean): void;
   usage(msg: string | null, description?: string | false): UsageInstance;
   version(ver: any): void;
   wrap(cols: number | null | undefined): void;

test/usage.cjs

@@ -3861,6 +3861,45 @@ describe('usage tests', () => {
           '  --uuid                                                              [required]',
         ]);
     });
+
+    // Addresses: https://github.com/yargs/yargs/issues/2030
+    it('should display options (with descriptions) on failed default command', () => {
+      const r = checkUsage(() =>
+        yargs('')
+          .command({
+            command: '$0 <arg1>',
+            desc: 'default desc',
+            builder: yargs =>
+              yargs
+                .option('arg1', {
+                  type: 'string',
+                  desc: 'arg1 desc',
+                  demandOption: true,
+                })
+                .option('arg2', {
+                  type: 'string',
+                  desc: 'arg2 desc',
+                }),
+            handler: noop,
+          })
+          .strict()
+          .parse()
+      );
+      console.log(r);
+      r.errors[0]
+        .split('\n')
+        .should.deep.equal([
+          'usage <arg1>',
+          '',
+          'default desc',
+          '',
+          'Options:',
+          '  --help     Show help                                                 [boolean]',
+          '  --version  Show version number                                       [boolean]',
+          '  --arg1     arg1 desc                                       [string] [required]',
+          '  --arg2     arg2 desc                                                  [string]',
+        ]);
+    });
   });
 
   describe('positional', () => {