fix: normalize exclude option, closes cypress-io#248

Author: bahmutov

common-utils.js

@@ -1,4 +1,12 @@
 // @ts-check
+function stringToArray(prop, obj) {
+  if (typeof obj[prop] === 'string') {
+    obj[prop] = [obj[prop]]
+  }
+
+  return obj
+}
+
 function combineNycOptions({
   pkgNycOptions,
   nycrc,
@@ -14,12 +22,10 @@ function combineNycOptions({
     pkgNycOptions
   )
 
-  if (typeof nycOptions.reporter === 'string') {
-    nycOptions.reporter = [nycOptions.reporter]
-  }
-  if (typeof nycOptions.extension === 'string') {
-    nycOptions.extension = [nycOptions.extension]
-  }
+  // normalize string and [string] props
+  stringToArray('reporter', nycOptions)
+  stringToArray('extension', nycOptions)
+  stringToArray('exclude', nycOptions)
 
   return nycOptions
 }

cypress/integration/combine-spec.js

@@ -63,4 +63,34 @@ describe('Combine NYC options', () => {
       exclude: ['bar.js']
     })
   })
+
+  it('converts exclude to array', () => {
+    // https://github.com/cypress-io/code-coverage/issues/248
+    const pkgNycOptions = {
+      all: true,
+      extension: '.js'
+    }
+    const nycrc = {
+      include: ['foo.js']
+    }
+    const nycrcJson = {
+      exclude: 'bar.js',
+      reporter: ['json']
+    }
+    const combined = combineNycOptions({
+      pkgNycOptions,
+      nycrc,
+      nycrcJson,
+      defaultNycOptions
+    })
+    cy.wrap(combined).should('deep.equal', {
+      all: true,
+      'report-dir': './coverage',
+      reporter: ['json'],
+      extension: ['.js'],
+      excludeAfterRemap: false,
+      include: ['foo.js'],
+      exclude: ['bar.js']
+    })
+  })
 })