diff --git a/mdformat_rustfmt/__init__.py b/mdformat_rustfmt/__init__.py
index f4aa609..983e15a 100644
--- a/mdformat_rustfmt/__init__.py
+++ b/mdformat_rustfmt/__init__.py
@@ -1,12 +1,27 @@
 __version__ = "0.0.3"  # DO NOT EDIT THIS LINE MANUALLY. LET bump2version UTILITY DO IT
 
+from collections.abc import Iterable
 import re
 import subprocess
 from typing import Callable
 
+in_commented = False
+
+
+def flatten(deep_list):
+    for el in deep_list:
+        if isinstance(el, Iterable) and not isinstance(el, (str, bytes)):
+            yield from flatten(el)
+        else:
+            yield el
+
 
 def format_rust(unformatted: str, _info_str: str) -> str:
+    global in_commented
+    global remove_newlines
+
     unformatted = _for_each_line(unformatted, _hide_sharp)
+
     unformatted_bytes = unformatted.encode("utf-8")
     result = subprocess.run(
         ["rustfmt"],
@@ -14,32 +29,108 @@ def format_rust(unformatted: str, _info_str: str) -> str:
         stderr=subprocess.DEVNULL,
         input=unformatted_bytes,
     )
-    if result.returncode:
-        raise Exception("Failed to format Rust code")
+
     formatted = result.stdout.decode("utf-8")
-    formatted = _for_each_line(formatted, _unhide_sharp)
-    return formatted
+
+    if result.returncode:
+        raise Exception("Failed to format Rust code\n" + formatted)
+
+    in_commented = False
+    remove_newlines = False
+
+    return _for_each_line(formatted, _unhide_sharp).replace("\r", "")
 
 
 def _for_each_line(string: str, action: Callable[[str], str]) -> str:
     lines = string.split("\n")
-    lines = (action(line) for line in lines)
+
+    lines = [action(line) for line in lines]
+
+    lines = list(flatten(lines))
+
+    lines = [x for x in lines if x is not None]
     return "\n".join(lines)
 
 
-_RUSTFMT_CUSTOM_COMMENT_PREFIX = "//#### "
+_RUSTFMT_CUSTOM_COMMENT_BLOCK_BEGIN = "//__MDFORMAT_RUSTFMT_COMMENT_BEGIN__"
+_RUSTFMT_CUSTOM_COMMENT_BLOCK_END = "//__MDFORMAT_RUSTFMT_COMMENT_END__"
+_RUSTFMT_CUSTOM_COMMENT_ESCAPE = "//__MDFORMAT_RUSTFMT_COMMENT_ESCAPE__"
+_RUSTFMT_CUSTOM_COMMENT_BLANK_LINE = "//__MDFORMAT_RUSTFMT_COMMENT_BLANK_LINE__"
 
 
-def _hide_sharp(line: str) -> str:
+def _hide_sharp(line: str):
+    global in_commented
     stripped = line.strip()
-    if stripped.startswith("# ") or stripped == "#":
-        return _RUSTFMT_CUSTOM_COMMENT_PREFIX + line
-    return line
 
+    if stripped.startswith("# ") or stripped.startswith("##") or stripped == "#":
+        tokens = []
+
+        if not in_commented:
+            in_commented = True
+            tokens.append(_RUSTFMT_CUSTOM_COMMENT_BLOCK_BEGIN)
+
+        if stripped.startswith("##"):
+            tokens.append(_RUSTFMT_CUSTOM_COMMENT_ESCAPE)
+
+        # if stripped == "#":
+        #     tokens.append(_RUSTFMT_CUSTOM_COMMENT_BLANK_LINE)
+
+        tokens.append(stripped[1:])
+
+        return tokens
+
+    if in_commented:
+        in_commented = False
+        return [_RUSTFMT_CUSTOM_COMMENT_BLOCK_END, stripped]
+
+    return stripped
+
+
+next_line_escape = False
+remove_newlines = False
+
+
+def _unhide_sharp(line: str):
+    global in_commented
+    global next_line_escape
+    global remove_newlines
+
+    if _RUSTFMT_CUSTOM_COMMENT_BLOCK_BEGIN in line:
+        remove_newlines = True
+        in_commented = True
+        line = re.sub(
+            re.escape(_RUSTFMT_CUSTOM_COMMENT_BLOCK_BEGIN), "", line, 1
+        ).rstrip()
+        return line or None
+
+    if _RUSTFMT_CUSTOM_COMMENT_BLOCK_END in line:
+        in_commented = False
+        line = re.sub(
+            re.escape(_RUSTFMT_CUSTOM_COMMENT_BLOCK_END), "", line, 1
+        ).rstrip()
+        return line or None
+
+    if _RUSTFMT_CUSTOM_COMMENT_ESCAPE in line:
+        next_line_escape = True
+        line = re.sub(re.escape(_RUSTFMT_CUSTOM_COMMENT_ESCAPE), "", line, 1).rstrip()
+        return line or None
+
+    if _RUSTFMT_CUSTOM_COMMENT_BLANK_LINE in line:
+        return "#"
+
+    if in_commented:
+        if line == "" and remove_newlines:
+            return None
+
+        remove_newlines = False
+
+        if line.startswith("#") and next_line_escape:
+            next_line_escape = False
+            return "#" + line
+
+        if line.startswith(" "):
+            return "#" + line[1:]
+
+        return "# " + line
 
-def _unhide_sharp(line: str) -> str:
-    if re.match(r"\s*" + re.escape(_RUSTFMT_CUSTOM_COMMENT_PREFIX), line):
-        # Remove the first "rustfmt custom comment prefix" and any leading
-        # whitespace the prefixed line originally had.
-        return re.sub(re.escape(_RUSTFMT_CUSTOM_COMMENT_PREFIX) + r"\s*", "", line, 1)
     return line
diff --git a/rustfmt.toml b/rustfmt.toml
new file mode 100644
index 0000000..1b4670e
--- /dev/null
+++ b/rustfmt.toml
@@ -0,0 +1 @@
+blank_lines_lower_bound = 1
diff --git a/tests/data/fixtures.md b/tests/data/fixtures.md
index 5f86195..4b47921 100644
--- a/tests/data/fixtures.md
+++ b/tests/data/fixtures.md
@@ -23,10 +23,131 @@ fn main() {
 .
 ```rust
 fn main() {
-    # let x=a();b();c();
+#   let x = a();
+#   b();
+#   c();
     let y = d();
     e();
     f();
 }
 ```
 .
+
+Format hidden lines
+.
+~~~rust
+fn main() {
+  #       let x=a();b();c();
+}
+~~~
+.
+```rust
+fn main() {
+#   let x = a();
+#   b();
+#   c();
+}
+```
+.
+
+Handle empty comment lines
+.
+~~~rust
+fn main() {
+  #
+#
+    # // comment
+let s = "asdf
+## literal hash";
+let x = 5;
+let y = 6;
+}
+~~~
+.
+```rust
+fn main() {
+#   // comment
+    let s = "asdf
+## literal hash";
+    let x = 5;
+    let y = 6;
+}
+```
+.
+
+Handle hidden derive and attr statements
+.
+~~~rust
+#   #[derive(Debug)]
+struct MyStruct {}
+~~~
+.
+```rust
+# #[derive(Debug)]
+struct MyStruct {}
+```
+.
+Handle derive and attr statements
+.
+~~~rust
+#[derive(Debug)]
+struct MyStruct {}
+~~~
+.
+```rust
+#[derive(Debug)]
+struct MyStruct {}
+```
+.
+[NIGHTLY] Preserve blank lines
+.
+~~~rust
+# struct Something {}
+#
+#
+# fn main() {}
+#
+#
+trait SomeTrait {   fn nothing() {} }
+ struct Another;
+
+ impl  Another {}
+~~~
+.
+```rust
+# struct Something {}
+# 
+# fn main() {}
+# 
+trait SomeTrait {
+    fn nothing() {}
+}
+
+struct Another;
+
+impl Another {}
+```
+.
+Comment collapse does not delete lines
+.
+~~~rust
+# fn main() -> Result<(), amethyst::Error> {
+#   let game_data = DispatcherBuilder::default().with_bundle(
+        // inside your rendering bundle setup
+        RenderingBundle::<DefaultBackend>::new()
+            .with_plugin(RenderFlat2D::default())
+#   )?;
+#   Ok(())
+# }
+~~~
+.
+```rust
+# fn main() -> Result<(), amethyst::Error> {
+#   let game_data = DispatcherBuilder::default().with_bundle(
+        // inside your rendering bundle setup
+        RenderingBundle::<DefaultBackend>::new().with_plugin(RenderFlat2D::default()),
+#   )?;
+#   Ok(())
+# }
+```
+.
\ No newline at end of file
diff --git a/tests/test_mdformat_rustfmt.py b/tests/test_mdformat_rustfmt.py
index 425902c..617a4e1 100644
--- a/tests/test_mdformat_rustfmt.py
+++ b/tests/test_mdformat_rustfmt.py
@@ -12,6 +12,8 @@
 )
 def test_fixtures(line, title, text, expected):
     """Test fixtures in tests/data/fixtures.md."""
+    if "NIGHTLY" in title:
+        pytest.skip("nightly test not supported on stable")
     md_new = mdformat.text(text, codeformatters={"rust"})
     if md_new != expected:
         print("Formatted (unexpected) Markdown below:")