From 60454bb4dea3122c8b63ed9d00ef8c8ce5016281 Mon Sep 17 00:00:00 2001
From: Asaf Amrami <asaf.amrami@gmail.com>
Date: Sun, 7 Feb 2021 13:33:45 +0200
Subject: [PATCH] fix: json FM ending with object parse error (#4909)

---
 .../src/formats/__tests__/frontmatter.spec.js        | 12 ++++++++++++
 packages/netlify-cms-core/src/formats/frontmatter.js |  5 +----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/packages/netlify-cms-core/src/formats/__tests__/frontmatter.spec.js b/packages/netlify-cms-core/src/formats/__tests__/frontmatter.spec.js
index 3a5d9a58..2f14d732 100644
--- a/packages/netlify-cms-core/src/formats/__tests__/frontmatter.spec.js
+++ b/packages/netlify-cms-core/src/formats/__tests__/frontmatter.spec.js
@@ -351,6 +351,18 @@ describe('Frontmatter', () => {
       });
     });
 
+    it('should parse JSON with { } delimiters ending with a nested object', () => {
+      expect(
+        FrontmatterInfer.fromFile(
+          '{\n  "title": "The Title",\n  "nested": {\n    "inside": "Inside prop"\n  }\n}\nContent',
+        ),
+      ).toEqual({
+        title: 'The Title',
+        nested: { inside: 'Inside prop' },
+        body: 'Content',
+      });
+    });
+
     it('should stringify JSON with { } delimiters when it is explicitly set as the format without a custom delimiter', () => {
       expect(
         frontmatterJSON().toFile({
diff --git a/packages/netlify-cms-core/src/formats/frontmatter.js b/packages/netlify-cms-core/src/formats/frontmatter.js
index be052f08..e120bfa7 100644
--- a/packages/netlify-cms-core/src/formats/frontmatter.js
+++ b/packages/netlify-cms-core/src/formats/frontmatter.js
@@ -13,10 +13,7 @@ const parsers = {
       let JSONinput = input.trim();
       // Fix JSON if leading and trailing brackets were trimmed.
       if (JSONinput.substr(0, 1) !== '{') {
-        JSONinput = '{' + JSONinput;
-      }
-      if (JSONinput.substr(-1) !== '}') {
-        JSONinput = JSONinput + '}';
+        JSONinput = '{' + JSONinput + '}';
       }
       return jsonFormatter.fromFile(JSONinput);
     },