From 003ad6fc2d28a53db3335237de02aa244cb9cbec Mon Sep 17 00:00:00 2001
From: Mike Donnalley <mdonnalley@salesforce.com>
Date: Tue, 19 Mar 2024 07:27:08 -0600
Subject: [PATCH] fix: show options when required flag or arg is not given a
 value (#1017)

---
 src/parser/errors.ts      |  7 ++++++-
 src/parser/parse.ts       |  4 ++++
 test/parser/parse.test.ts | 21 +++++++++++++++++++--
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/parser/errors.ts b/src/parser/errors.ts
index 98551bf73..3b3de0063 100644
--- a/src/parser/errors.ts
+++ b/src/parser/errors.ts
@@ -58,7 +58,12 @@ export class RequiredArgsError extends CLIParseError {
     let message = `Missing ${args.length} required arg${args.length === 1 ? '' : 's'}`
     const namedArgs = args.filter((a) => a.name)
     if (namedArgs.length > 0) {
-      const list = renderList(namedArgs.map((a) => [a.name, a.description] as [string, string]))
+      const list = renderList(
+        namedArgs.map((a) => {
+          const description = a.options ? `(${a.options.join('|')}) ${a.description}` : a.description
+          return [a.name, description]
+        }),
+      )
       message += `:\n${list}`
     }
 
diff --git a/src/parser/parse.ts b/src/parser/parse.ts
index eefd9ea1c..237447142 100644
--- a/src/parser/parse.ts
+++ b/src/parser/parse.ts
@@ -188,6 +188,10 @@ export class Parser<
 
         // if the value ends up being one of the command's flags, the user didn't provide an input
         if (typeof input !== 'string' || this.findFlag(input).name) {
+          if (flag.options) {
+            throw new CLIError(`Flag --${name} expects one of these values: ${flag.options.join(', ')}`)
+          }
+
           throw new CLIError(`Flag --${name} expects a value`)
         }
 
diff --git a/test/parser/parse.test.ts b/test/parser/parse.test.ts
index 6f136dffb..abcb3f178 100644
--- a/test/parser/parse.test.ts
+++ b/test/parser/parse.test.ts
@@ -146,6 +146,23 @@ describe('parse', () => {
         }
       })
 
+      it('throws error when no value provided to required flag with options', async () => {
+        try {
+          await parse(['--myflag', '--second', 'value'], {
+            flags: {
+              myflag: Flags.string({
+                required: true,
+                options: ['a', 'b'],
+              }),
+              second: Flags.string(),
+            },
+          })
+          assert.fail('should have thrown')
+        } catch (error) {
+          expect((error as CLIError).message).to.include('Flag --myflag expects one of these values: a, b')
+        }
+      })
+
       it('throws error when no value provided to required flag before a short char flag', async () => {
         try {
           await parse(['--myflag', '-s', 'value'], {
@@ -270,7 +287,7 @@ describe('parse', () => {
           await parse(['arg1'], {
             args: {
               arg1: Args.string({required: true}),
-              arg2: Args.string({required: true, description: 'arg2 desc'}),
+              arg2: Args.string({required: true, description: 'arg2 desc', options: ['a', 'b']}),
               arg3: Args.string({required: true, description: 'arg3 desc'}),
             },
           })
@@ -279,7 +296,7 @@ describe('parse', () => {
         }
 
         expect(message).to.include(`Missing 2 required args:
-arg2  arg2 desc
+arg2  (a|b) arg2 desc
 arg3  arg3 desc
 See more help with --help`)
       })