fix: Prevent Cypress from crashing when argument parsing "spec: {}" (#18312)

packages/server/__snapshots__/args_spec.js

@@ -21,3 +21,11 @@ You passed: xyz
 
 The error was: Cannot read property 'split' of undefined
 `
+
+exports['invalid spec error'] = `
+Cypress encountered an error while parsing the argument spec
+
+You passed: [object Object]
+
+The error was: spec must be a string or comma-separated list
+`

packages/server/lib/util/args.js

@@ -247,22 +247,29 @@ module.exports = {
     }
 
     if (spec) {
-      const resolvePath = (p) => {
-        return path.resolve(options.cwd, p)
-      }
-
-      // https://github.com/cypress-io/cypress/issues/8818
-      // Sometimes spec is parsed to array. Because of that, we need check.
-      if (typeof spec === 'string') {
-        // clean up single quotes wrapping the spec for Windows users
-        // https://github.com/cypress-io/cypress/issues/2298
-        if (spec[0] === '\'' && spec[spec.length - 1] === '\'') {
-          spec = spec.substring(1, spec.length - 1)
+      try {
+        const resolvePath = (p) => {
+          return path.resolve(options.cwd, p)
         }
 
-        options.spec = strToArray(spec).map(resolvePath)
-      } else {
-        options.spec = spec.map(resolvePath)
+        // https://github.com/cypress-io/cypress/issues/8818
+        // Sometimes spec is parsed to array. Because of that, we need check.
+        if (typeof spec === 'string') {
+          // clean up single quotes wrapping the spec for Windows users
+          // https://github.com/cypress-io/cypress/issues/2298
+          if (spec[0] === '\'' && spec[spec.length - 1] === '\'') {
+            spec = spec.substring(1, spec.length - 1)
+          }
+
+          options.spec = strToArray(spec).map(resolvePath)
+        } else {
+          options.spec = spec.map(resolvePath)
+        }
+      } catch (err) {
+        debug('could not pass config spec value %s', spec)
+        debug('error %o', err)
+
+        return errors.throw('COULD_NOT_PARSE_ARGUMENTS', 'spec', spec, 'spec must be a string or comma-separated list')
       }
     }
 

packages/server/test/unit/args_spec.js

@@ -152,6 +152,18 @@ describe('lib/util/args', () => {
 
       expect(options.spec[0]).to.eq(`${cwd}/cypress/integration/foo_spec.js`)
     })
+
+    it('throws if argument cannot be parsed', function () {
+      expect(() => {
+        return this.setup('--run-project', 'foo', '--spec', {})
+      }).to.throw
+
+      try {
+        return this.setup('--run-project', 'foo', '--spec', {})
+      } catch (err) {
+        return snapshot('invalid spec error', stripAnsi(err.message))
+      }
+    })
   })
 
   context('--tag', () => {