From e1966fcff33e95993a95bbaace4920077d7422fd Mon Sep 17 00:00:00 2001
From: John Gee <john@ruru.gen.nz>
Date: Tue, 21 Apr 2020 18:29:06 +1200
Subject: [PATCH] Omit the help flags from help that are masked by other
 options (#1247)

---
 index.js                   | 28 ++++++++++++++++++++++------
 tests/command.help.test.js | 16 ++++++++++++++++
 2 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/index.js b/index.js
index c36df5367..987b79f0d 100644
--- a/index.js
+++ b/index.js
@@ -1401,17 +1401,33 @@ class Command extends EventEmitter {
 
   optionHelp() {
     const width = this.padWidth();
-
     const columns = process.stdout.columns || 80;
     const descriptionWidth = columns - width - 4;
+    function padOptionDetails(flags, description) {
+      return pad(flags, width) + '  ' + optionalWrap(description, descriptionWidth, width + 2);
+    };
 
-    // Append the help information
-    return this.options.map((option) => {
+    // Explicit options (including version)
+    const help = this.options.map((option) => {
       const fullDesc = option.description +
         ((!option.negate && option.defaultValue !== undefined) ? ' (default: ' + JSON.stringify(option.defaultValue) + ')' : '');
-      return pad(option.flags, width) + '  ' + optionalWrap(fullDesc, descriptionWidth, width + 2);
-    }).concat([pad(this._helpFlags, width) + '  ' + optionalWrap(this._helpDescription, descriptionWidth, width + 2)])
-      .join('\n');
+      return padOptionDetails(option.flags, fullDesc);
+    });
+
+    // Implicit help
+    const showShortHelpFlag = this._helpShortFlag && !this._findOption(this._helpShortFlag);
+    const showLongHelpFlag = !this._findOption(this._helpLongFlag);
+    if (showShortHelpFlag || showLongHelpFlag) {
+      let helpFlags = this._helpFlags;
+      if (!showShortHelpFlag) {
+        helpFlags = this._helpLongFlag;
+      } else if (!showLongHelpFlag) {
+        helpFlags = this._helpShortFlag;
+      }
+      help.push(padOptionDetails(helpFlags, this._helpDescription));
+    }
+
+    return help.join('\n');
   };
 
   /**
diff --git a/tests/command.help.test.js b/tests/command.help.test.js
index f484254a7..58b146f07 100644
--- a/tests/command.help.test.js
+++ b/tests/command.help.test.js
@@ -114,3 +114,19 @@ test('when addCommand with hidden:true then not displayed in helpInformation', (
   const helpInformation = program.helpInformation();
   expect(helpInformation).not.toMatch('secret');
 });
+
+test('when help short flag masked then not displayed in helpInformation', () => {
+  const program = new commander.Command();
+  program
+    .option('-h, --host', 'select host');
+  const helpInformation = program.helpInformation();
+  expect(helpInformation).not.toMatch(/\W-h\W.*display help/);
+});
+
+test('when both help flags masked then not displayed in helpInformation', () => {
+  const program = new commander.Command();
+  program
+    .option('-h, --help', 'custom');
+  const helpInformation = program.helpInformation();
+  expect(helpInformation).not.toMatch('display help');
+});