feat(fmt): better error on malfored HTML files (#25853)

Improves syntax errors for HTML formatter.

`broken.html`

```html
<div class=container > content 
```

```
$ deno fmt broken.html
Error formatting: /Users/ib/dev/deno/tests/specs/fmt/html/broken.html
   syntax error 'expect close tag' at line 3, column 0
Checked 1 file
```

```
$ ./target/debug/deno fmt broken.html
Error formatting: /Users/ib/dev/deno/tests/specs/fmt/html/broken.html
   Syntax error (expect close tag) at file:///Users/ib/dev/deno/tests/specs/fmt/html/broken.html:3:0

Checked 1 file
```

cli/tools/fmt.rs

@@ -33,6 +33,7 @@ use deno_core::error::AnyError;
 use deno_core::futures;
 use deno_core::parking_lot::Mutex;
 use deno_core::unsync::spawn_blocking;
+use deno_core::url::Url;
 use log::debug;
 use log::info;
 use log::warn;
@@ -435,7 +436,39 @@ pub fn format_html(
     },
   )
   .map_err(|error| match error {
-    markup_fmt::FormatError::Syntax(error) => AnyError::from(error),
+    markup_fmt::FormatError::Syntax(error) => {
+      // TODO(bartlomieju): rework when better error support in `markup_fmt` lands
+      fn inner(
+        error: &markup_fmt::SyntaxError,
+        file_path: &Path,
+      ) -> Option<String> {
+        let error_str = format!("{}", error);
+        let error_str = error_str.strip_prefix("syntax error '")?;
+
+        let reason = error_str
+          .split("' at")
+          .collect::<Vec<_>>()
+          .first()
+          .map(|s| s.to_string())?;
+
+        let url = Url::from_file_path(file_path).ok()?;
+
+        let error_msg = format!(
+          "Syntax error ({}) at {}:{}:{}\n",
+          reason,
+          url.as_str(),
+          error.line,
+          error.column
+        );
+        Some(error_msg)
+      }
+
+      if let Some(error_msg) = inner(&error, file_path) {
+        AnyError::from(generic_error(error_msg))
+      } else {
+        AnyError::from(error)
+      }
+    }
     markup_fmt::FormatError::External(errors) => {
       let last = errors.len() - 1;
       AnyError::msg(

tests/specs/fmt/html/__test__.jsonc

@@ -8,6 +8,10 @@
     "well_formatted": {
       "args": "fmt --check well_formatted.html",
       "output": "Checked 1 file\n"
+    },
+    "broken": {
+      "args": "fmt broken.html",
+      "output": "broken.out"
     }
   }
 }

tests/specs/fmt/html/broken.html

@@ -0,0 +1,2 @@
+<div class=container > content 
+

tests/specs/fmt/html/broken.out

@@ -0,0 +1,4 @@
+Error formatting: [WILDCARD]broken.html
+   Syntax error (expect close tag) at file://[WILDCARD]broken.html:3:0
+
+Checked 1 file