Add JSON as default Accept

Author: NicoLaval

README.md

@@ -32,7 +32,7 @@ The API supports DDI-specific response formats only. Use the `Accept` header to
 
 **DDI JSON Format (default):**
 ```bash
-# DDI JSON format (default if no Accept header)
+# DDI JSON format (default - no Accept header needed)
 curl https://api.example.com/ddi/v1/variables
 
 # Explicit DDI JSON request
@@ -41,12 +41,12 @@ curl -H "Accept: application/vnd.ddi.structure+json;version=3.3" https://api.exa
 
 **DDI XML Format:**
 ```bash
-# DDI XML format
+# DDI XML format (requires Accept header)
 curl -H "Accept: application/vnd.ddi.structure+xml;version=3.3" https://api.example.com/ddi/v1/variables
 ```
 
 **Supported Content Types:**
-- `application/vnd.ddi.structure+json;version=3.3` - DDI JSON format (default)
+- `application/vnd.ddi.structure+json;version=3.3` - DDI JSON format (default if no Accept header)
 - `application/vnd.ddi.structure+xml;version=3.3` - DDI XML format
 
 **Note:** 

ddi-rest.yaml

@@ -9,6 +9,14 @@ info:
     
     DDI is an international standard for describing statistical and social science data.
     
+    ## Response Formats
+    
+    The API supports DDI-specific response formats:
+    - `application/vnd.ddi.structure+json;version=3.3` - DDI JSON format (default if no Accept header is provided)
+    - `application/vnd.ddi.structure+xml;version=3.3` - DDI XML format
+    
+    If no `Accept` header is provided, the API returns DDI JSON format by default.
+    
 servers:
   - description: Mock API Server
     url: http://ddi-api.making-sense.info/ddi/v1
@@ -54,6 +62,8 @@ paths:
         Variables describe the structure of data elements within a dataset. They include information such as name, label, description, and references to associated concepts.
         
         Variables can be filtered by various criteria including study, dataset, or concept references.
+        
+        **Response Format**: If no `Accept` header is provided, returns DDI JSON format (`application/vnd.ddi.structure+json;version=3.3`) by default.
       parameters:
         - $ref: "#/components/parameters/urn"
         - $ref: "#/components/parameters/agencyID"
@@ -84,6 +94,8 @@ paths:
         - An ID (if agencyID and version are provided as query parameters)
         
         Returns detailed information about the variable including its structure, concepts, and related metadata.
+        
+        **Response Format**: If no `Accept` header is provided, returns DDI JSON format (`application/vnd.ddi.structure+json;version=3.3`) by default.
       parameters:
         - $ref: "#/components/parameters/variableID-path"
         - $ref: "#/components/parameters/agencyID"
@@ -885,7 +897,10 @@ components:
 
   responses:
     "200-variables":
-      description: OK - List of variables
+      description: |
+        OK - List of variables.
+        
+        **Default format**: If no `Accept` header is provided, returns DDI JSON format (`application/vnd.ddi.structure+json;version=3.3`).
       content:
         application/vnd.ddi.structure+xml;version=3.3:
           description: |
@@ -933,6 +948,7 @@ components:
                </l:Variable>
             </g:ResourcePackage>
         application/vnd.ddi.structure+json;version=3.3:
+          description: DDI JSON format (default if no Accept header is provided)
           schema:
             type: array
             items:
@@ -986,6 +1002,7 @@ components:
                </l:Variable>
             </g:ResourcePackage>
         application/vnd.ddi.structure+json;version=3.3:
+          description: DDI JSON format (default if no Accept header is provided)
           schema:
             $ref: "#/components/schemas/Variable"
     "200-concepts":

docs/MOCK_API_ENDPOINTS.md

@@ -21,7 +21,9 @@ The mock API supports DDI-specific formats only:
 - **DDI JSON** (default): `application/vnd.ddi.structure+json;version=3.3`
 - **DDI XML**: `application/vnd.ddi.structure+xml;version=3.3`
 
-The format is determined by the `Accept` header in your request. If no `Accept` header is provided, DDI JSON format is returned by default.
+The format is determined by the `Accept` header in your request. 
+
+**Default Behavior**: If no `Accept` header is provided (or if `Accept: */*` is sent), the API returns DDI JSON format by default. You don't need to specify the `Accept` header to get JSON responses.
 
 **Note:** Generic formats (`application/json`, `application/xml`, `text/xml`) are not supported and will return a `406 Not Acceptable` error.
 

mocks/server.js

@@ -366,17 +366,20 @@ function resolveReferences(obj, level, startDepth = 0) {
 // Helper to determine response format based on Accept header
 function getResponseFormat(req) {
   const accept = req.headers.accept || '';
+  
+  // If no Accept header or Accept is */*, default to DDI JSON
+  if (!accept || accept === '*/*' || accept.trim() === '') {
+    return 'json';
+  }
+  
   // Only accept DDI-specific formats
   if (accept.includes('application/vnd.ddi.structure+xml;version=3.3')) {
     return 'xml';
   }
   if (accept.includes('application/vnd.ddi.structure+json;version=3.3')) {
     return 'json';
   }
-  // Default to JSON DDI format if no Accept header
-  if (!accept || accept === '*/*') {
-    return 'json';
-  }
+  
   // Unsupported format
   return null;
 }