From 17598c5c2c4b7f1e6e638cf495c0f73efff1901b Mon Sep 17 00:00:00 2001
From: Jordan Pittman <jordan@cryptica.me>
Date: Sun, 1 Sep 2024 20:53:49 -0400
Subject: [PATCH] port: CSS serializer

---
 crates/core/src/css/mod.rs        |   1 +
 crates/core/src/css/serializer.rs | 159 ++++++++++++++++++++++++++++++
 2 files changed, 160 insertions(+)
 create mode 100644 crates/core/src/css/serializer.rs

diff --git a/crates/core/src/css/mod.rs b/crates/core/src/css/mod.rs
index ff50e5d1f..8881bd4c6 100644
--- a/crates/core/src/css/mod.rs
+++ b/crates/core/src/css/mod.rs
@@ -1,2 +1,3 @@
 pub mod ast;
+pub mod serializer;
 pub mod visit;
diff --git a/crates/core/src/css/serializer.rs b/crates/core/src/css/serializer.rs
new file mode 100644
index 000000000..99d055351
--- /dev/null
+++ b/crates/core/src/css/serializer.rs
@@ -0,0 +1,159 @@
+use super::ast::{CssNode, Stylesheet};
+
+impl Stylesheet {
+  pub fn to_css(&self) -> Vec<u8> {
+    self.rules.to_css()
+  }
+}
+
+impl CssNode {
+  fn to_css(&self) -> Vec<u8> {
+    let mut css: Vec<u8> = vec![];
+    self.write_css_to(&mut css, 0);
+    return css;
+  }
+
+  fn write_css_to(&self, css: &mut Vec<u8>, depth: usize) {
+    let indent = b"  ".repeat(depth);
+
+    match self {
+      CssNode::Comment { value } => {
+        css.extend(&indent);
+        css.extend(b"/*");
+        css.extend(value);
+        css.extend(b"*/\n");
+      },
+
+      CssNode::Declaration { property, value, important } => {
+        css.extend(&indent);
+        css.extend(property);
+        css.extend(b": ");
+        css.extend(value);
+        if *important {
+          css.extend(b" !important");
+        }
+        css.extend(b";\n");
+      },
+
+      CssNode::Context { nodes, .. } => {
+        for child in nodes {
+          child.write_css_to(css, depth);
+        }
+      },
+
+      CssNode::Contents { nodes } => {
+        for child in nodes {
+          child.write_css_to(css, depth);
+        }
+      },
+
+      CssNode::AtRule { name, params, nodes } => {
+        css.extend(&indent);
+        css.extend(b"@");
+        css.extend(name);
+        css.extend(b" ");
+        css.extend(params);
+
+        // Print at-rules without nodes with a `;` instead of an empty block.
+        //
+        // E.g.:
+        //
+        // ```css
+        // @layer base, components, utilities;
+        // ```
+        if nodes.is_empty() {
+          css.extend(b";\n");
+        } else {
+          css.extend(b" {\n");
+
+          for child in nodes {
+            child.write_css_to(css, depth + 1);
+          }
+
+          css.extend(&indent);
+          css.extend(b"}\n");
+        }
+      },
+
+      CssNode::StyleRule { selector, nodes } => {
+        css.extend(&indent);
+        css.extend(selector);
+        css.extend(b" {\n");
+
+        for child in nodes {
+          child.write_css_to(css, depth + 1);
+        }
+
+        css.extend(&indent);
+        css.extend(b"}\n");
+      }
+    }
+  }
+}
+
+#[cfg(test)]
+mod test {
+  use crate::css::{ast::{comment, decl}, parser::parse};
+
+  #[test]
+  fn should_pretty_print_an_ast() {
+    let css = parse(b".foo{color:red;&:hover{color:blue;}}").unwrap();
+
+    assert_eq!(css.to_css(), b".foo {\n  color: red;\n  &:hover {\n    color: blue;\n  }\n}\n");
+  }
+
+  #[test]
+  fn should_print_decls() {
+    let css = decl(b"color", "red", false);
+    assert_eq!(css.to_css(), b"color: red;\n");
+  }
+
+  #[test]
+  fn should_print_decls_important() {
+    let css = decl(b"color", "red", true);
+    assert_eq!(css.to_css(), b"color: red !important;\n");
+  }
+
+  #[test]
+  fn should_print_comments() {
+    let css = comment(b" hello world ");
+
+    assert_eq!(css.to_css(), b"/* hello world */\n");
+  }
+
+  #[test]
+  fn should_print_at_rules_without_a_body() {
+    let css = parse(b"@layer base, components, utilities;").unwrap();
+    assert_eq!(css.to_css(), b"@layer base, components, utilities;\n");
+  }
+
+  #[test]
+  fn should_print_at_rules_with_a_body() {
+    let css = parse(b"@layer base { color: red; }").unwrap();
+    assert_eq!(css.to_css(), b"@layer base {\n  color: red;\n}\n");
+  }
+
+  #[test]
+  fn should_print_at_rules_with_a_body_and_nested_rules() {
+    let css = parse(b"@layer base { color: red; &:hover { color: blue; } }").unwrap();
+    assert_eq!(css.to_css(), b"@layer base {\n  color: red;\n  &:hover {\n    color: blue;\n  }\n}\n");
+  }
+
+  #[test]
+  fn should_print_style_rules() {
+    let css = parse(b".foo { color: red; }").unwrap();
+    assert_eq!(css.to_css(), b".foo {\n  color: red;\n}\n");
+  }
+
+  #[test]
+  fn should_print_style_rules_with_nested_style_rules() {
+    let css = parse(b".foo { color: red; &:hover { color: blue; } }").unwrap();
+    assert_eq!(css.to_css(), b".foo {\n  color: red;\n  &:hover {\n    color: blue;\n  }\n}\n");
+  }
+
+  #[test]
+  fn should_print_style_rules_with_nested_at_rules() {
+    let css = parse(b".foo { color: red; @layer base { color: blue; } }").unwrap();
+    assert_eq!(css.to_css(), b".foo {\n  color: red;\n  @layer base {\n    color: blue;\n  }\n}\n");
+  }
+}