Format comments with topiary

Author: bbannier

format_zeek/src/lib.rs

@@ -92,14 +92,25 @@ fn format_zeek(m: &Bound<'_, PyModule>) -> PyResult<()> {
 
 #[cfg(test)]
 mod test {
+    use insta::assert_debug_snapshot;
+
     use crate::FormatError;
 
     fn format(input: &str) -> Result<String, FormatError> {
         crate::format(input, false, false)
     }
 
     #[test]
-    fn expression() {
-        assert_eq!(format("1+1;").unwrap(), "1+1;\n");
+    fn comments() {
+        assert_debug_snapshot!(format("# foo\n;1;"));
+        assert_debug_snapshot!(format("##! foo\n;1;"));
+        assert_debug_snapshot!(format("## foo\n1;"));
+        assert_debug_snapshot!(format("##< foo\n1;"));
+
+        assert_debug_snapshot!(format("1;# foo\n;1;"));
+        assert_debug_snapshot!(format("1;##! foo\n;1;"));
+        assert_debug_snapshot!(format("1;## foo\n1;"));
+        assert_debug_snapshot!(format("1;##< foo"));
+        assert_debug_snapshot!(format("1;##< foo\n##< bar"));
     }
 }

format_zeek/src/query.scm

@@ -0,0 +1,37 @@
+; Rules for formatting Spicy.
+;
+; Formatting is specified here in terms of tree-sitter nodes. We select nodes
+; with tree-sitter queries[^1] and then attach topiary formatting rules[^2] in
+; the captures.
+;
+; See the Development section in README.md for a workflow on how to modify or
+; extend these rules.
+
+; [^1]: https://tree-sitter.github.io/tree-sitter/using-parsers#pattern-matching-with-queries
+; [^2]: https://github.com/tweag/topiary#design
+
+; Comments are always followed by a linebreak.
+[
+  (minor_comment)
+  (zeekygen_head_comment)
+  (zeekygen_prev_comment)
+  (zeekygen_next_comment)
+] @append_hardline
+
+; Comments are preceeded by a space.
+(
+  [
+    (_)
+    (nl) @do_nothing
+  ]
+  .
+  [
+    (minor_comment)
+    (zeekygen_head_comment)
+    (zeekygen_prev_comment)
+    (zeekygen_next_comment)
+  ] @prepend_space
+)
+
+; If we have multiple comments documenting an item with `##<` align them all.
+(zeekygen_prev_comment) @multi_line_indent_all

format_zeek/src/snapshots/format_zeek__test__comments-2.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"##! foo\\n;1;\")"
+---
+Ok(
+    "##! foo\n;1;\n",
+)

format_zeek/src/snapshots/format_zeek__test__comments-3.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"## foo\\n1;\")"
+---
+Ok(
+    "## foo\n1;\n",
+)

format_zeek/src/snapshots/format_zeek__test__comments-4.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"##< foo\\n1;\")"
+---
+Ok(
+    "##< foo\n1;\n",
+)

format_zeek/src/snapshots/format_zeek__test__comments-5.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"1;# foo\\n;1;\")"
+---
+Ok(
+    "1; # foo\n;1;\n",
+)

format_zeek/src/snapshots/format_zeek__test__comments-6.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"1;##! foo\\n;1;\")"
+---
+Ok(
+    "1; ##! foo\n;1;\n",
+)

format_zeek/src/snapshots/format_zeek__test__comments-7.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"1;## foo\\n1;\")"
+---
+Ok(
+    "1; ## foo\n1;\n",
+)

format_zeek/src/snapshots/format_zeek__test__comments-8.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"1;##< foo\")"
+---
+Ok(
+    "1; ##< foo\n",
+)

format_zeek/src/snapshots/format_zeek__test__comments-9.snap

@@ -0,0 +1,7 @@
+---
+source: src/lib.rs
+expression: "format(\"1;##< foo\\n##< bar\")"
+---
+Ok(
+    "1; ##< foo\n##< bar\n",
+)