Improve missing Content-Type header error message

closes #1
jshttp · Feb 13, 2015 · d7d6424 · d7d6424
1 parent 3126696
commit d7d6424
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Showing 4 changed files with 22 additions and 5 deletions.
diff --git a/HISTORY.md b/HISTORY.md
@@ -1,3 +1,8 @@
+unreleased
+==========
+
+  * Improve missing `Content-Type` header error message
+
 1.0.0 / 2015-02-01
 ==================
 

diff --git a/README.md b/README.md
@@ -35,6 +35,8 @@ properties (examples are shown for the string `'image/svg+xml; charset=utf-8'`):
  - `parameters`: An object of the parameters in the media type (name of parameter
    always lower case). Example: `{charset: 'utf-8'}`
 
+Throws a `TypeError` if the string is missing or invalid.
+
 ### contentType.parse(req)
 
 ```js
@@ -44,6 +46,8 @@ var obj = contentType.parse(req)
 Parse the `content-type` header from the given `req`. Short-cut for
 `contentType.parse(req.headers['content-type'])`.
 
+Throws a `TypeError` if the `Content-Type` header is missing or invalid.
+
 ### contentType.parse(res)
 
 ```js
@@ -53,6 +57,8 @@ var obj = contentType.parse(res)
 Parse the `content-type` header set on the given `res`. Short-cut for
 `contentType.parse(res.getHeader('content-type'))`.
 
+Throws a `TypeError` if the `Content-Type` header is missing or invalid.
+
 ### contentType.format(obj)
 
 ```js
@@ -68,6 +74,8 @@ shown that produce the string `'image/svg+xml; charset=utf-8'`):
  - `parameters`: An object of the parameters in the media type (name of the
    parameter will be lower-cased). Example: `{charset: 'utf-8'}`
 
+Throws a `TypeError` if the object contains an invalid type or parameter names.
+
 ## License
 
 [MIT](LICENSE)

diff --git a/index.js b/index.js
@@ -106,9 +106,13 @@ function parse(string) {
     throw new TypeError('argument string is required')
   }
 
-  // support req/res-like objects as argument
   if (typeof string === 'object') {
+    // support req/res-like objects as argument
     string = getcontenttype(string)
+
+    if (typeof string !== 'string') {
+      throw new TypeError('content-type header is missing from object');
+    }
   }
 
   if (typeof string !== 'string') {

diff --git a/test/contentType_parse.js b/test/contentType_parse.js
@@ -117,12 +117,12 @@ describe('contentType.parse(req)', function () {
   })
 
   it('should reject objects without headers property', function () {
-    assert.throws(contentType.parse.bind(null, {}), /argument string is required/)
+    assert.throws(contentType.parse.bind(null, {}), /content-type header is missing/)
   })
 
   it('should reject missing content-type', function () {
     var req = {headers: {}}
-    assert.throws(contentType.parse.bind(null, req), /argument string is required/)
+    assert.throws(contentType.parse.bind(null, req), /content-type header is missing/)
   })
 })
 
@@ -134,11 +134,11 @@ describe('contentType.parse(res)', function () {
   })
 
   it('should reject objects without getHeader method', function () {
-    assert.throws(contentType.parse.bind(null, {}), /argument string is required/)
+    assert.throws(contentType.parse.bind(null, {}), /content-type header is missing/)
   })
 
   it('should reject missing content-type', function () {
     var res = {getHeader: function(){}}
-    assert.throws(contentType.parse.bind(null, res), /argument string is required/)
+    assert.throws(contentType.parse.bind(null, res), /content-type header is missing/)
   })
 })