Add JSON Content-Type on import if it doesn't include it

packages/insomnia-app/app/common/import.js

@@ -179,7 +179,23 @@ export async function importRaw(
       continue;
     }
 
-    const existingDoc = await model.getById(resource._id);
+    // Try adding Content-Type JSON if no Content-Type exists
+    if (
+      model.type === models.request.type &&
+      resource.body &&
+      typeof resource.body.text === 'string' &&
+      Array.isArray(resource.headers) &&
+      !resource.headers.find(h => h.name.toLowerCase() === 'content-type')
+    ) {
+      try {
+        JSON.parse(resource.body.text);
+        resource.headers.push({ name: 'Content-Type', value: 'application/json' });
+      } catch (err) {
+        // Not JSON
+      }
+    }
+
+    const existingDoc = await db.get(model.type, resource._id);
     let newDoc: BaseModel;
     if (existingDoc) {
       newDoc = await db.docUpdate(existingDoc, resource);