9 files changed, 92 insertions, 12 deletions
diff --git a/cli/tests/badly_formatted.json b/cli/tests/badly_formatted.json
new file mode 100644
index 000000000..f2bacf73d
--- /dev/null
+++ b/cli/tests/badly_formatted.json
@@ -0,0 +1,12 @@
+{
+
+
+  "key1":     "value1",
+          "key2": true,
+          "key3": ["value2",     "value3", false],
+          "keys": {
+            "more": "values"
+          }
+
+
+}
+\ No newline at end of file
diff --git a/cli/tests/badly_formatted.md b/cli/tests/badly_formatted.md
index adffe3e46..26afe483b 100644
--- a/cli/tests/badly_formatted.md
+++ b/cli/tests/badly_formatted.md
@@ -25,4 +25,22 @@ hello(        "alice");
 function foo(): number {
   return       2;
 }
+```
+
+```jsonc
+
+{
+  // Comment in JSON
+  "key":          "value",
+                "key2":      
+                "value2",
+}
+
+```
+
+```json
+{
+  "numbers":
+  ["1",      "2"]
+}
 ```
 \ No newline at end of file
diff --git a/cli/tests/badly_formatted_fixed.json b/cli/tests/badly_formatted_fixed.json
new file mode 100644
index 000000000..0d697a2c6
--- /dev/null
+++ b/cli/tests/badly_formatted_fixed.json
@@ -0,0 +1,8 @@
+{
+  "key1": "value1",
+  "key2": true,
+  "key3": ["value2", "value3", false],
+  "keys": {
+    "more": "values"
+  }
+}
diff --git a/cli/tests/badly_formatted_fixed.md b/cli/tests/badly_formatted_fixed.md
index 359a8aead..8ba74cac3 100644
--- a/cli/tests/badly_formatted_fixed.md
+++ b/cli/tests/badly_formatted_fixed.md
@@ -21,3 +21,17 @@ function foo(): number {
   return 2;
 }
 ```
+
+```jsonc
+{
+  // Comment in JSON
+  "key": "value",
+  "key2": "value2"
+}
+```
+
+```json
+{
+  "numbers": ["1", "2"]
+}
+```
diff --git a/cli/tests/fmt/expected_fmt_check_formatted_files.out b/cli/tests/fmt/expected_fmt_check_formatted_files.out
index 7c1e471b9..5a4833dd4 100644
--- a/cli/tests/fmt/expected_fmt_check_formatted_files.out
+++ b/cli/tests/fmt/expected_fmt_check_formatted_files.out
@@ -1 +1 @@
-Checked 3 files
+Checked 4 files
diff --git a/cli/tests/fmt/expected_fmt_check_ignore.out b/cli/tests/fmt/expected_fmt_check_ignore.out
index 158c556c2..7c1e471b9 100644
--- a/cli/tests/fmt/expected_fmt_check_ignore.out
+++ b/cli/tests/fmt/expected_fmt_check_ignore.out
@@ -1 +1 @@
-Checked 2 files
+Checked 3 files
diff --git a/cli/tests/fmt/expected_fmt_check_tests_dir.out b/cli/tests/fmt/expected_fmt_check_tests_dir.out
index e2dc2b4ae..fe84cd485 100644
--- a/cli/tests/fmt/expected_fmt_check_tests_dir.out
+++ b/cli/tests/fmt/expected_fmt_check_tests_dir.out
@@ -1,2 +1,2 @@
 [WILDCARD]
-error: Found 6 not formatted files in [WILDCARD] files
+error: Found 7 not formatted files in [WILDCARD] files
diff --git a/cli/tests/fmt/formatted4.jsonc b/cli/tests/fmt/formatted4.jsonc
new file mode 100644
index 000000000..f0f72a6ed
--- /dev/null
+++ b/cli/tests/fmt/formatted4.jsonc
@@ -0,0 +1,4 @@
+{
+  // Comment
+  "key": "value"
+}
diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index 988372b17..b55111154 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -496,30 +496,43 @@ mod integration {
   fn fmt_test() {
     let t = TempDir::new().expect("tempdir fail");
     let fixed_js = util::root_path().join("cli/tests/badly_formatted_fixed.js");
-    let fixed_md = util::root_path().join("cli/tests/badly_formatted_fixed.md");
     let badly_formatted_original_js =
       util::root_path().join("cli/tests/badly_formatted.mjs");
-    let badly_formatted_original_md =
-      util::root_path().join("cli/tests/badly_formatted.md");
     let badly_formatted_js = t.path().join("badly_formatted.js");
-    let badly_formatted_md = t.path().join("badly_formatted.md");
     let badly_formatted_js_str = badly_formatted_js.to_str().unwrap();
-    let badly_formatted_md_str = badly_formatted_md.to_str().unwrap();
     std::fs::copy(&badly_formatted_original_js, &badly_formatted_js)
       .expect("Failed to copy file");
+
+    let fixed_md = util::root_path().join("cli/tests/badly_formatted_fixed.md");
+    let badly_formatted_original_md =
+      util::root_path().join("cli/tests/badly_formatted.md");
+    let badly_formatted_md = t.path().join("badly_formatted.md");
+    let badly_formatted_md_str = badly_formatted_md.to_str().unwrap();
     std::fs::copy(&badly_formatted_original_md, &badly_formatted_md)
       .expect("Failed to copy file");
+
+    let fixed_json =
+      util::root_path().join("cli/tests/badly_formatted_fixed.json");
+    let badly_formatted_original_json =
+      util::root_path().join("cli/tests/badly_formatted.json");
+    let badly_formatted_json = t.path().join("badly_formatted.json");
+    let badly_formatted_json_str = badly_formatted_json.to_str().unwrap();
+    std::fs::copy(&badly_formatted_original_json, &badly_formatted_json)
+      .expect("Failed to copy file");
     // First, check formatting by ignoring the badly formatted file.
     let status = util::deno_cmd()
       .current_dir(util::root_path())
       .arg("fmt")
       .arg(format!(
-        "--ignore={},{}",
-        badly_formatted_js_str, badly_formatted_md_str
+        "--ignore={},{},{}",
+        badly_formatted_js_str,
+        badly_formatted_md_str,
+        badly_formatted_json_str
       ))
       .arg("--check")
       .arg(badly_formatted_js_str)
       .arg(badly_formatted_md_str)
+      .arg(badly_formatted_json_str)
       .spawn()
       .expect("Failed to spawn script")
       .wait()
@@ -532,6 +545,7 @@ mod integration {
       .arg("--check")
       .arg(badly_formatted_js_str)
       .arg(badly_formatted_md_str)
+      .arg(badly_formatted_json_str)
       .spawn()
       .expect("Failed to spawn script")
       .wait()
@@ -543,6 +557,7 @@ mod integration {
       .arg("fmt")
       .arg(badly_formatted_js_str)
       .arg(badly_formatted_md_str)
+      .arg(badly_formatted_json_str)
       .spawn()
       .expect("Failed to spawn script")
       .wait()
@@ -550,10 +565,13 @@ mod integration {
     assert!(status.success());
     let expected_js = std::fs::read_to_string(fixed_js).unwrap();
     let expected_md = std::fs::read_to_string(fixed_md).unwrap();
+    let expected_json = std::fs::read_to_string(fixed_json).unwrap();
     let actual_js = std::fs::read_to_string(badly_formatted_js).unwrap();
     let actual_md = std::fs::read_to_string(badly_formatted_md).unwrap();
+    let actual_json = std::fs::read_to_string(badly_formatted_json).unwrap();
     assert_eq!(expected_js, actual_js);
     assert_eq!(expected_md, actual_md);
+    assert_eq!(expected_json, actual_json);
   }
 
   mod file_watcher {
@@ -2838,7 +2856,7 @@ console.log("finish");
   });
 
   itest!(fmt_check_tests_dir {
-    args: "fmt --check ./",
+    args: "fmt --check ./ --ignore=.test_coverage",
     output: "fmt/expected_fmt_check_tests_dir.out",
     exit_code: 1,
   });
@@ -2850,7 +2868,7 @@ console.log("finish");
   });
 
   itest!(fmt_check_formatted_files {
-    args: "fmt --check fmt/formatted1.js fmt/formatted2.ts fmt/formatted3.md",
+    args: "fmt --check fmt/formatted1.js fmt/formatted2.ts fmt/formatted3.md fmt/formatted4.jsonc",
     output: "fmt/expected_fmt_check_formatted_files.out",
     exit_code: 0,
   });
@@ -2875,6 +2893,12 @@ console.log("finish");
     ),
   });
 
+  itest!(fmt_stdin_json {
+    args: "fmt --ext=json -",
+    input: Some("{    \"key\":   \"value\"}"),
+    output_str: Some("{ \"key\": \"value\" }\n"),
+  });
+
   itest!(fmt_stdin_check_formatted {
     args: "fmt --check -",
     input: Some("const a = 1;\n"),