# Test content type, ignoring charset?

**URL:** <https://community.postman.com/t/test-content-type-ignoring-charset/953>\
**Category:** Help Hub\
**Tags:** tests\
**Created:** [February 15, 2018, 8:31pm UTC](https://community.postman.com/t/test-content-type-ignoring-charset/953 "2018-02-15T20:31:23Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![lsloan\_umich](https://sea2.discourse-cdn.com/getpostman/user_avatar/community.postman.com/lsloan_umich/32/280_2.png) [@lsloan\_umich](https://community.postman.com/u/lsloan_umich)\
**Post date:** [February 15, 2018, 8:31pm UTC](https://community.postman.com/t/test-content-type-ignoring-charset/953/1 "2018-02-15T20:31:23Z")

</div>

I want to test the Content-Type of a response is “text/html”. I thought that type was being returned, but this test kept failing:

```
    pm.response.to.have.header('Content-Type', 'text/html');

```

I examined the response closely and I found that the value of the header was actually, “text/html; charset=utf-8”.

For my purposes, the “charset” is unimportant. How can I test the type is correct, regardless of the “charset” value?

---

<div class="post-metadata">

**Author:** ![rmlira](https://sea2.discourse-cdn.com/getpostman/user_avatar/community.postman.com/rmlira/32/232_2.png) [@rmlira](https://community.postman.com/u/rmlira)\
**Post date:** [February 16, 2018, 12:15pm UTC](https://community.postman.com/t/test-content-type-ignoring-charset/953/2 "2018-02-16T12:15:14Z")

</div>

Hi.

You could make:

pm.test(“Response has a valid Content-Type header”, function() {  
pm.response.to.have.header(“Content-Type”);  
pm.expect(pm.response.headers.get(“Content-Type”)).to.include(“text/html”);  
});

Or you could store pm.response.headers.get(“Content-Type”) in a var and check with js indexOf

---

<div class="post-metadata">

**Author:** ![lsloan\_umich](https://sea2.discourse-cdn.com/getpostman/user_avatar/community.postman.com/lsloan_umich/32/280_2.png) [@lsloan\_umich](https://community.postman.com/u/lsloan_umich)\
**Post date:** [February 16, 2018, 2:23pm UTC](https://community.postman.com/t/test-content-type-ignoring-charset/953/3 "2018-02-16T14:23:05Z")

</div>

Thanks. Looks like a good suggestion. I’ll give it a try.

I wonder: Is the “to.have.header()” test necessary? If the response didn’t have the right header, wouldn’t the following “to.include()” test fail anyway?

PS: A note for other forum readers… When I copied this example and pasted it into Postman, I discovered this forum changes plain quotes (`"…"`) into “pretty” or “smart” quotes (`“…”`). Copy and paste with caution! (I wonder whether there is a setting to disable those quotes.)

---

<div class="post-metadata">

**Author:** ![lsloan\_umich](https://sea2.discourse-cdn.com/getpostman/user_avatar/community.postman.com/lsloan_umich/32/280_2.png) [@lsloan\_umich](https://community.postman.com/u/lsloan_umich)\
**Post date:** [February 20, 2018, 10:10pm UTC](https://community.postman.com/t/test-content-type-ignoring-charset/953/4 "2018-02-20T22:10:49Z")

</div>

Nobody answered my question, so I’ll make a guess.

The test could be written without `to.have.header()`:

```auto
pm.test('Response has a valid Content-Type header', function() {
  pm.expect(pm.response.headers.get('content-type')).to.include('text/html');
});

```

However, if the response doesn’t have a “Content-Type” header, the test will produce the error, “`AssertionError: object tested must be an array, a map, an object, a set, a string, or a weakset, but undefined given`”.

That’s not a very easy error message to understand. So, the recommendation is to test specifically for the presence of the header first:

```auto
pm.test('Response has a valid Content-Type header', function() {
  pm.response.to.have.header('content-type');
  pm.expect(pm.response.headers.get('content-type')).to.include('text/html');
});

```

Written this way, if the “Content-Type” header isn’t available, the error message will be, “`AssertionError: expected response to have header with key 'content-type'`”, which is much easier to understand.

Additionally, I found that `include()` is not the ideal function to test the header for this value. The function is case-sensitive, but standards say that case is unimportant in MIME types. `text/html`, `Text/HTML`, and `tExT/HtML` are all equivalent. A safer test would use `match()` instead, with a case-insensitive regular expression:

```auto
pm.test('Response has a valid Content-Type header', function() {
  pm.response.to.have.header('content-type');
  // case-insensitive and rooted at the beginning of the string
  pm.expect(pm.response.headers.get('content-type')).match(/^text\/html/i);
});

```