Fixed IDE not opening JSON files

app/assets/javascripts/ide/services/index.js

@@ -18,7 +18,7 @@ export default {
     return axios
       .get(file.rawPath, {
-        params: { format: 'json' },
+        transformResponse: [f => f],
       })
       .then(({ data }) => data);
   },
@@ -33,7 +33,7 @@ export default {
     return axios
       .get(file.rawPath.replace(`/raw/${file.branchId}/${file.path}`, `/raw/${sha}/${file.path}`), {
-        params: { format: 'json' },
+        transformResponse: [f => f],
       })
       .then(({ data }) => data);
   },

changelogs/unreleased/ide-edit-json-files.yml

+---
+title: Fixed IDE not opening JSON files
+merge_request: 20798
+author:
+type: fixed

spec/javascripts/ide/stores/actions/file_spec.js

@@ -366,6 +366,23 @@ describe('IDE store file actions', () => {
       });
     });
+    describe('return JSON', () => {
+      beforeEach(() => {
+        mock.onGet(/(.*)/).replyOnce(200, JSON.stringify({ test: '123' }));
+      });
+
+      it('does not parse returned JSON', done => {
+        store
+          .dispatch('getRawFileData', { path: tmpFile.path })
+          .then(() => {
+            expect(tmpFile.raw).toEqual('{"test":"123"}');
+
+            done();
+          })
+          .catch(done.fail);
+      });
+    });
+
     describe('error', () => {
       beforeEach(() => {
         mock.onGet(/(.*)/).networkError();