GraphQL body in Postman - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this GraphQL query body in Postman?

Given this GraphQL query body sent in Postman, what will be the value of the "data" field in the response if the server returns the user's name and age correctly?

Postman

{
  "query": "query { user(id: \"123\") { name age } }"
}

A {"data":{"user":{"name":"Alice"}}}

B {"error":"User not found"}

C {"data":{"user":{"name":"Alice","age":30}}}

D {"data":{"user":null}}

💡 Hint

The query requests both name and age fields for user with id 123.

The query asks for user with id 123 and requests name and age fields. If the server returns both correctly, the data field will contain both name and age.

❓ assertion

intermediate

Which assertion correctly verifies the user's email in Postman test script?

You want to check that the user's email returned by this GraphQL query is "[e-mail]". Which Postman test script assertion is correct?

Postman

pm.test("User email is correct", function () {
  const jsonData = pm.response.json();
  // Assertion here
});

A pm.expect(jsonData.user.email).to.eql('[e-mail]');

B pm.expect(jsonData.data.user.email).to.eql('[e-mail]');

C pm.expect(jsonData.data.email).to.eql('[e-mail]');

D pm.expect(jsonData.data.user.email).to.equal('[e-mail]');

💡 Hint

The GraphQL response nests user inside data.

The GraphQL response structure nests the user object inside the data field. The correct path to email is jsonData.data.user.email. The expected email is '[e-mail]'.

❓ locator

advanced

Which JSON path correctly locates the 'posts' array in a GraphQL response body?

Given this GraphQL response body, which JSON path expression correctly locates the 'posts' array inside the 'user' object?

Postman

{
  "data": {
    "user": {
      "id": "123",
      "posts": [
        {"id": "p1", "title": "Post 1"},
        {"id": "p2", "title": "Post 2"}
      ]
    }
  }
}

A $.data.user.posts

B $.user.posts

C $.data.posts

D $.posts

💡 Hint

The 'posts' array is inside 'user', which is inside 'data'.

The JSON path must start from the root '$', then go to 'data', then 'user', then 'posts'. So the correct path is $.data.user.posts.

🔧 Debug

advanced

Why does this GraphQL query body cause a syntax error in Postman?

This GraphQL query body is sent in Postman but causes a syntax error. Identify the cause.

Postman

{
  "query": "query { user(id: 123) { name age } }"
}

A The query keyword is missing

B The age field is not allowed in the query

C The braces around user are incorrect

D The user id 123 should be a string with quotes: \"123\"

💡 Hint

GraphQL requires string arguments to be quoted.

In GraphQL, string arguments must be enclosed in double quotes. The id 123 is unquoted, causing a syntax error.

❓ framework

expert

Which Postman test script correctly validates that the 'posts' array has exactly 3 items?

You receive this GraphQL response body in Postman. Which test script correctly asserts that the 'posts' array inside 'user' has exactly 3 items?

Postman

{
  "data": {
    "user": {
      "posts": [
        {"id": "p1"},
        {"id": "p2"},
        {"id": "p3"}
      ]
    }
  }
}

A pm.test('Posts count is 3', () => { const jsonData = pm.response.json(); pm.expect(jsonData.data.user.posts).to.have.lengthOf(3); });

B pm.test('Posts count is 3', () => { const jsonData = pm.response.json(); pm.expect(jsonData.data.user.posts.length).to.eql(3); });

C pm.test('Posts count is 3', () => { const jsonData = pm.response.json(); pm.expect(jsonData.data.user.posts.count).to.eql(3); });

D pm.test('Posts count is 3', () => { const jsonData = pm.response.json(); pm.expect(jsonData.data.user.posts.size).to.eql(3); });

💡 Hint

Use the correct Chai assertion for array length in Postman.

In Postman test scripts, to check array length, use 'to.have.lengthOf()'. Using '.length' property with 'to.eql()' works but is less idiomatic. The '.count' and '.size' properties do not exist on arrays.