feat: Allow explicit null encoding for readFile/writeFile

packages/driver/cypress/integration/commands/files_spec.js

@@ -37,6 +37,21 @@ describe('src/cy/commands/files', () => {
       })
     })
 
+    it('passes explicit null encoding through to server and decodes response', () => {
+      Cypress.backend.resolves({
+        contents: Buffer.from('\n').toString('base64'),
+        filePath: '/path/to/foo.json',
+      })
+
+      cy.readFile('foo.json', null).then(() => {
+        expect(Cypress.backend).to.be.calledWith(
+          'read:file',
+          'foo.json',
+          { encoding: null },
+        )
+      }).should('eql', Buffer.from('\n'))
+    })
+
     it('sets the contents as the subject', () => {
       Cypress.backend.resolves(okResponse)
 
@@ -340,6 +355,22 @@ describe('src/cy/commands/files', () => {
       })
     })
 
+    it('explicit null encoding is sent to server as base64 string', () => {
+      Cypress.backend.resolves(okResponse)
+
+      cy.writeFile('foo.txt', Buffer.from([0, 0, 54, 255]), null).then(() => {
+        expect(Cypress.backend).to.be.calledWith(
+          'write:file',
+          'foo.txt',
+          'AAA2/w==',
+          {
+            encoding: 'base64',
+            flag: 'w',
+          },
+        )
+      })
+    })
+
     it('can take encoding as part of options', () => {
       Cypress.backend.resolves(okResponse)
 

packages/driver/src/cy/commands/files.ts

@@ -11,11 +11,11 @@ export default (Commands, Cypress, cy) => {
 
       if (_.isObject(encoding)) {
         userOptions = encoding
-        encoding = null
+        encoding = undefined
       }
 
       options = _.defaults({}, userOptions, {
-        encoding: encoding != null ? encoding : 'utf8',
+        encoding: encoding === undefined ? 'utf8' : encoding,
         log: true,
       })
 
@@ -53,6 +53,10 @@ export default (Commands, Cypress, cy) => {
             args: { cmd: 'readFile', action: 'read', file, filePath: err.filePath, error: err.message },
           })
         }).then(({ contents, filePath }) => {
+          if (options.encoding === null) {
+            contents = Buffer.from(contents, 'base64')
+          }
+
           consoleProps['File Path'] = filePath
           consoleProps['Contents'] = contents
 
@@ -85,11 +89,11 @@ export default (Commands, Cypress, cy) => {
 
       if (_.isObject(encoding)) {
         userOptions = encoding
-        encoding = null
+        encoding = undefined
       }
 
       options = _.defaults({}, userOptions, {
-        encoding: encoding ? encoding : 'utf8',
+        encoding: encoding === undefined ? 'utf8' : encoding,
         flag: userOptions.flag ? userOptions.flag : 'w',
         log: true,
       })
@@ -120,6 +124,11 @@ export default (Commands, Cypress, cy) => {
         })
       }
 
+      if (Buffer.isBuffer(contents)) {
+        contents = contents.toString('base64')
+        options.encoding = 'base64'
+      }
+
       if (_.isObject(contents)) {
         contents = JSON.stringify(contents, null, 2)
       }

packages/server/lib/files.js

@@ -6,10 +6,10 @@ module.exports = {
     const filePath = path.resolve(projectRoot, file)
     const readFn = path.extname(filePath) === '.json' ? fs.readJsonAsync : fs.readFileAsync
 
-    return readFn(filePath, options.encoding || 'utf8')
+    return readFn(filePath, options.encoding === undefined ? 'utf8' : options.encoding)
     .then((contents) => {
       return {
-        contents,
+        contents: options.encoding === null ? contents.toString('base64') : contents,
         filePath,
       }
     })
@@ -22,7 +22,7 @@ module.exports = {
   writeFile (projectRoot, file, contents, options = {}) {
     const filePath = path.resolve(projectRoot, file)
     const writeOptions = {
-      encoding: options.encoding || 'utf8',
+      encoding: options.encoding === undefined ? 'utf8' : options.encoding,
       flag: options.flag || 'w',
     }
 

packages/server/test/unit/files_spec.js

@@ -41,6 +41,12 @@ describe('lib/files', () => {
       })
     })
 
+    it('explicit null encoding is sent to driver as base64 string', function () {
+      return files.readFile(this.projectRoot, 'tests/_fixtures/ascii.foo', { encoding: null }).then(({ contents }) => {
+        expect(contents).to.eql(Buffer.from('\n').toString('base64'))
+      })
+    })
+
     it('parses json to valid JS object', function () {
       return files.readFile(this.projectRoot, 'tests/_fixtures/users.json').then(({ contents }) => {
         expect(contents).to.eql([
@@ -75,6 +81,14 @@ describe('lib/files', () => {
       })
     })
 
+    it('explicit null encoding is read from driver as base64 string', function () {
+      return files.writeFile(this.projectRoot, '.projects/write_file.txt', Buffer.from(''), { encoding: null }).then(() => {
+        return files.readFile(this.projectRoot, '.projects/write_file.txt', { encoding: null }).then(({ contents }) => {
+          expect(contents).to.eql(Buffer.from('').toString('base64'))
+        })
+      })
+    })
+
     it('overwrites existing file by default', function () {
       return files.writeFile(this.projectRoot, '.projects/write_file.txt', 'foo').then(() => {
         return files.readFile(this.projectRoot, '.projects/write_file.txt').then(({ contents }) => {