Reading file contents in Cypress - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read a file named 'example.txt' using Cypress.

Cypress

cy.[1]('example.txt').then((content) => {
  expect(content).to.exist
})

Drag options to blanks, or click blank then click option'

AreadFile

BwriteFile

Cvisit

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'writeFile' instead of 'readFile'.

Using 'visit' which is for URLs, not files.

The readFile command reads the contents of a file in Cypress.

2fill in blank

medium

Complete the code to assert that the file content includes the word 'Hello'.

Cypress

cy.readFile('example.txt').then((content) => {
  expect(content).to.[1]('Hello')
})

Drag options to blanks, or click blank then click option'

Aequal

Bhave.length

Cbe.empty

Dinclude

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'equal' which requires exact match.

Using 'be.empty' which checks for empty content.

The include assertion checks if the string contains the given substring.

3fill in blank

hard

Fix the error in the code to correctly read a JSON file and assert a property value.

Cypress

cy.readFile('data.json').then((data) => {
  expect(data.[1]).to.equal('John')
})

Drag options to blanks, or click blank then click option'

Ausername

BName

Cname

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Name' with uppercase 'N' which does not match the JSON property.

Using unrelated property names like 'username' or 'user'.

The JSON file has a property named name (all lowercase), so we access it as data.name.

4fill in blank

hard

Fill both blanks to read a file and assert its length is greater than 10.

Cypress

cy.readFile('log.txt').then((content) => {
  expect(content.[1]).to.[2](10)
})

Drag options to blanks, or click blank then click option'

Alength

Bbe.greaterThan

Cbe.lessThan

Dlength()

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'length()' which is not a property but a method (strings use property).

Using 'be.lessThan' which checks for smaller values.

The length property gives the string length, and be.greaterThan asserts it is more than 10.

5fill in blank

hard

Fill all three blanks to read a JSON file, filter users older than 18, and assert the count.

Cypress

cy.readFile('users.json').then((users) => {
  const adults = users.filter(user => user.[1] [2] 18)
  expect(adults.[3]).to.equal(3)
})

Drag options to blanks, or click blank then click option'

Aage

B>

Clength

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'name' instead of 'age' for filtering.

Using '<' instead of '>' operator.

Checking 'length()' instead of 'length' property.

We filter by the age property, use the greater than operator >, and check the length of the filtered array.

Practice

1. What is the primary purpose of cy.readFile() in Cypress testing?

easy

A. To read the contents of a file during a test

B. To write data to a file during a test

C. To delete a file before running tests

D. To upload a file to the server

Solution

1. Step 1: Understand the function name

   cy.readFile() suggests reading a file, not writing or deleting.

2. Step 2: Recall Cypress documentation

   This command reads file contents so tests can verify data inside files.

3. Final Answer:

   To read the contents of a file during a test -> Option A

4. Quick Check:

   cy.readFile() reads file contents [OK]

Hint: Remember: readFile reads, writeFile writes [OK]

Common Mistakes:

• Confusing readFile with writeFile
• Thinking it uploads files
• Assuming it deletes files

2. Which of the following is the correct syntax to read a JSON file named data.json using Cypress?

easy

A. cy.readFile('data.json', 'utf8')

B. cy.readFile('data.json').then((content) => { /* use content */ })

C. cy.readFile('data.json').catch((content) => { /* use content */ })

D. cy.readFile('data.json').write((content) => { /* use content */ })

Solution

1. Step 1: Identify correct method chaining

   Using then() after cy.readFile() is correct to access file content.

2. Step 2: Check other options

   catch() is for errors, not normal reading; write() is invalid here; passing 'utf8' alone is incomplete.

3. Final Answer:

   cy.readFile('data.json').then((content) => { /* use content */ }) -> Option B

4. Quick Check:

   Use then() to handle readFile content [OK]

Hint: Use then() to access file content after readFile [OK]

Common Mistakes:

• Using catch() instead of then()
• Trying to write after readFile
• Passing encoding without then()

3. Given the code below, what will be logged to the console if example.txt contains the text "Hello Cypress"?

cy.readFile('example.txt').then((text) => {
  console.log(text);
});

medium

A. Empty string

B. undefined

C. An error because readFile needs JSON

D. "Hello Cypress"

Solution

1. Step 1: Understand readFile behavior

   cy.readFile() reads file content as text by default if file is plain text.

2. Step 2: Check the file content

   The file contains "Hello Cypress", so the callback receives this string and logs it.

3. Final Answer:

   "Hello Cypress" -> Option D

4. Quick Check:

   readFile logs file text content [OK]

Hint: readFile returns file content as string for text files [OK]

Common Mistakes:

• Assuming readFile only works with JSON
• Expecting undefined instead of content
• Thinking it throws error for text files

4. Identify the error in the following Cypress code snippet that tries to read a file and assert its content:

cy.readFile('config.json').then((data) => {
  expect(data).to.equal('config');
});

medium

A. Incorrect file path syntax

B. Missing catch() to handle errors

C. Using to.equal() instead of to.deep.equal() for object comparison

D. readFile cannot be used with JSON files

Solution

1. Step 1: Understand data type returned by readFile

   Reading a JSON file returns an object, not a string.

2. Step 2: Check assertion method

   to.equal() checks strict equality, which fails for objects; to.deep.equal() is needed for object content comparison.

3. Final Answer:

   Using to.equal() instead of to.deep.equal() for object comparison -> Option C

4. Quick Check:

   Use deep.equal for object assertions [OK]

Hint: Use deep.equal for objects, equal for primitives [OK]

Common Mistakes:

• Using to.equal() for objects
• Ignoring error handling
• Assuming readFile can't read JSON

5. You want to verify that a text file notes.txt contains the word "important" anywhere in its content using Cypress. Which code snippet correctly performs this check?

hard

A. cy.readFile('notes.txt').then((text) => { expect(text.includes('important')).to.be.true; })

B. cy.readFile('notes.txt').should('contain', 'important')

C. cy.readFile('notes.txt').then((text) => { expect(text).to.equal('important'); })

D. cy.readFile('notes.txt').then((text) => { expect(text).to.have.property('important'); })

Solution

1. Step 1: Understand file content check

   We want to check if the word "important" is anywhere in the text, so we need to check substring presence.

2. Step 2: Evaluate options

   cy.readFile('notes.txt').then((text) => { expect(text.includes('important')).to.be.true; }) uses includes() and asserts true, which is correct. cy.readFile('notes.txt').should('contain', 'important') is invalid because should('contain') is for DOM elements, not file content. cy.readFile('notes.txt').then((text) => { expect(text).to.equal('important'); }) checks exact equality, which is wrong. cy.readFile('notes.txt').then((text) => { expect(text).to.have.property('important'); }) wrongly uses to.have.property() on a string.

3. Final Answer:

   cy.readFile('notes.txt').then((text) => { expect(text.includes('important')).to.be.true; }) -> Option A

4. Quick Check:

   Use includes() to check substring in file text [OK]

Hint: Use includes() inside then() to check text content [OK]

Common Mistakes:

• Using should('contain') on file content
• Checking exact equality instead of substring
• Using property assertion on string