Show help on unknown option 837 (#1615)

* cli: if user passed unknown option, show help and exit, close #837

* cli: test unknown option output

* linting

cli/__snapshots__/cli_spec.js

@@ -168,3 +168,84 @@ exports['cli -v no binary version 1'] = `
 Cypress package version: 1.2.3
 Cypress binary version: not installed
 `
+
+exports['shows help for open --foo 1'] = `
+
+  command: bin/cypress open --foo
+  code: 1
+  failed: true
+  killed: false
+  signal: null
+  timedOut: false
+
+  stdout:
+  -------
+  error: unknown option: --foo
+
+
+  Usage: open [options]
+
+  Opens Cypress in the interactive GUI.
+
+
+  Options:
+
+    -p, --port <port>             runs Cypress on a specific port. overrides any value in cypress.json.
+    -e, --env <env>               sets environment variables. separate multiple values with a comma. overrides any value in cypress.json or cypress.env.json
+    -c, --config <config>         sets configuration values. separate multiple values with a comma. overrides any value in cypress.json.
+    -d, --detached [bool]         runs Cypress application in detached mode
+    -P, --project <project path>  path to the project
+    --global                      force Cypress into global mode as if its globally installed
+    --dev                         runs cypress in development and bypasses binary check
+    -h, --help                    output usage information
+  -------
+  stderr:
+  -------
+  
+  -------
+  
+`
+
+exports['shows help for run --foo 1'] = `
+
+  command: bin/cypress run --foo
+  code: 1
+  failed: true
+  killed: false
+  signal: null
+  timedOut: false
+
+  stdout:
+  -------
+  error: unknown option: --foo
+
+
+  Usage: run [options]
+
+  Runs Cypress tests from the CLI without the GUI
+
+
+  Options:
+
+    --record [bool]                            records the run. sends test results, screenshots and videos to your Cypress Dashboard.
+    --headed                                   displays the Electron browser instead of running headlessly
+    -k, --key <record-key>                     your secret Record Key. you can omit this if you set a CYPRESS_RECORD_KEY environment variable.
+    -s, --spec <spec>                          runs a specific spec file. defaults to "all"
+    -r, --reporter <reporter>                  runs a specific mocha reporter. pass a path to use a custom reporter. defaults to "spec"
+    -o, --reporter-options <reporter-options>  options for the mocha reporter. defaults to "null"
+    -p, --port <port>                          runs Cypress on a specific port. overrides any value in cypress.json.
+    -e, --env <env>                            sets environment variables. separate multiple values with a comma. overrides any value in cypress.json or cypress.env.json
+    -c, --config <config>                      sets configuration values. separate multiple values with a comma. overrides any value in cypress.json.
+    -b, --browser <browser-name>               runs Cypress in the browser with the given name. note: using an external browser will not record a video.
+    -P, --project <project-path>               path to the project
+    --group                                    flag to group individual runs by using common --group-id
+    --group-id <group-id>                      optional common id to group runs by, extracted from CI environment variables by default
+    --dev                                      runs cypress in development and bypasses binary check
+    -h, --help                                 output usage information
+  -------
+  stderr:
+  -------
+  
+  -------
+  
+`

cli/lib/cli.js

@@ -5,6 +5,18 @@ const debug = require('debug')('cypress:cli')
 const util = require('./util')
 const logger = require('./logger')
 
+// patch "commander" method called when a user passed an unknown option
+// we want to print help for the current command and exit with an error
+commander.Command.prototype.unknownOption = function (flag) {
+  if (this._allowUnknownOption) return
+  logger.error()
+  logger.error('  error: unknown option:', flag)
+  logger.error()
+  this.outputHelp()
+  logger.error()
+  process.exit(1)
+}
+
 const coerceFalse = (arg) => {
   return arg !== 'false'
 }

cli/package.json

@@ -78,7 +78,7 @@
     "nock": "^9.0.9",
     "shelljs": "0.7.8",
     "sinon": "3.2.1",
-    "snap-shot-it": "4.0.1",
+    "snap-shot-it": "4.1.4",
     "strip-ansi": "4.0.0"
   },
   "files": [

cli/test/lib/cli_spec.js

@@ -22,6 +22,21 @@ describe('cli', function () {
     this.exec = (args) => cli.init(`node test ${args}`.split(' '))
   })
 
+  context('unknown option', () => {
+    // note it shows help for that specific command
+    it('shows help', () =>
+      execa('bin/cypress', ['open', '--foo']).then((result) => {
+        snapshot('shows help for open --foo', result)
+      })
+    )
+
+    it('shows help for run command', () =>
+      execa('bin/cypress', ['run', '--foo']).then((result) => {
+        snapshot('shows help for run --foo', result)
+      })
+    )
+  })
+
   context('help command', () => {
     it('shows help', () =>
       execa('bin/cypress', ['help']).then(snapshot)