From c509e648c646e4654e6be4e56081a46c70b8c573 Mon Sep 17 00:00:00 2001
From: Corey Farrell <git@cfware.com>
Date: Mon, 6 May 2019 10:27:36 -0400
Subject: [PATCH] fix(cli): Report error if unwanted positional arguments are
 received

This applies to check-coverage, instrument, merge and report.  Passing
additional arguments will now cause the help script to be displayed and
an error exit code.

Unknown flags `nyc report --unknown=1` are still not reported.
Reporting unknown flags would require additional work as
`yargs.strict()` causes unknown items from configuration to be reported,
including flags that are defined for the global command but not a
sub-command.

Fixes #401
---
 lib/commands/check-coverage.js | 1 +
 lib/commands/instrument.js     | 9 +++++++++
 lib/commands/merge.js          | 1 +
 lib/commands/report.js         | 1 +
 test/nyc-integration.js        | 4 ++--
 5 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/commands/check-coverage.js b/lib/commands/check-coverage.js
index 6b12341b7..62dfb9081 100644
--- a/lib/commands/check-coverage.js
+++ b/lib/commands/check-coverage.js
@@ -7,6 +7,7 @@ exports.describe = 'check whether coverage is within thresholds provided'
 
 exports.builder = function (yargs) {
   yargs
+    .demandCommand(0, 0)
     .option('exclude', {
       alias: 'x',
       default: testExclude.defaultExclude,
diff --git a/lib/commands/instrument.js b/lib/commands/instrument.js
index f744faef6..701dcb6f7 100644
--- a/lib/commands/instrument.js
+++ b/lib/commands/instrument.js
@@ -9,6 +9,15 @@ exports.describe = 'instruments a file or a directory tree and writes the instru
 
 exports.builder = function (yargs) {
   return yargs
+    .demandCommand(0, 0)
+    .positional('input', {
+      describe: 'file or directory to instrument',
+      type: 'text'
+    })
+    .positional('output', {
+      describe: 'directory to output instrumented files',
+      type: 'text'
+    })
     .option('require', {
       alias: 'i',
       default: [],
diff --git a/lib/commands/merge.js b/lib/commands/merge.js
index 072cfc450..98c6ff2d0 100644
--- a/lib/commands/merge.js
+++ b/lib/commands/merge.js
@@ -11,6 +11,7 @@ exports.describe = 'merge istanbul format coverage output in a given folder'
 
 exports.builder = function (yargs) {
   return yargs
+    .demandCommand(0, 0)
     .positional('input-directory', {
       describe: 'directory containing multiple istanbul coverage files',
       type: 'text',
diff --git a/lib/commands/report.js b/lib/commands/report.js
index 739ff30dc..345983d23 100644
--- a/lib/commands/report.js
+++ b/lib/commands/report.js
@@ -7,6 +7,7 @@ exports.describe = 'run coverage report for .nyc_output'
 
 exports.builder = function (yargs) {
   return yargs
+    .demandCommand(0, 0)
     .option('reporter', {
       alias: 'r',
       describe: 'coverage reporter(s) to use',
diff --git a/test/nyc-integration.js b/test/nyc-integration.js
index 86937e7aa..c4e0d9064 100644
--- a/test/nyc-integration.js
+++ b/test/nyc-integration.js
@@ -45,11 +45,11 @@ t.test('--check-coverage fails when the expected coverage is below a threshold',
 }))
 
 // https://github.com/istanbuljs/nyc/issues/384
-t.test('--check-coverage fails when check-coverage command is used rather than flag', t => {
+t.test('check-coverage command is equivalent to the flag', t => {
   return testSuccess(t, {
     args: [process.execPath, './half-covered.js']
   }).then(() => testFailure(t, {
-    args: ['check-coverage', '--lines', '51', process.execPath, './half-covered.js']
+    args: ['check-coverage', '--lines', '51']
   }))
 })