refactor(prettier): impl Display for Doc (#1401)

crates/oxc_prettier/src/doc.rs

@@ -3,7 +3,8 @@
 //! References:
 //! * <https://github.com/prettier/prettier/blob/main/commands.md>
 
-use oxc_allocator::{Allocator, Box, String, Vec};
+use oxc_allocator::{Box, String, Vec};
+use std::fmt;
 
 use crate::{array, line, ss, Prettier};
 
@@ -34,73 +35,6 @@ pub enum Doc<'a> {
     IfBreak(Box<'a, Doc<'a>>),
 }
 
-pub struct DocPrinter<'a> {
-    allocator: &'a Allocator,
-}
-
-impl<'a> DocPrinter<'a> {
-    pub fn new(allocator: &'a Allocator) -> Self {
-        Self { allocator }
-    }
-
-    pub fn print(&mut self, doc: &Doc<'a>) -> String {
-        let mut str = String::new_in(self.allocator);
-        match doc {
-            Doc::Str(s) => {
-                str.push('"');
-                str.push_str(s);
-                str.push('"');
-            }
-            Doc::Array(docs) => {
-                str.push('[');
-                for (idx, doc) in docs.iter().enumerate() {
-                    str.push_str(&self.print(doc));
-                    if idx != docs.len() - 1 {
-                        str.push_str(", ");
-                    }
-                }
-                str.push(']');
-            }
-            Doc::Indent(contents) => {
-                str.push_str("indent([");
-                for (idx, doc) in contents.iter().enumerate() {
-                    str.push_str(&self.print(doc));
-                    if idx != contents.len() - 1 {
-                        str.push_str(", ");
-                    }
-                }
-                str.push_str("])");
-            }
-            Doc::Group(contents) => {
-                str.push_str("group([");
-                for (idx, doc) in contents.iter().enumerate() {
-                    str.push_str(&self.print(doc));
-                    if idx != contents.len() - 1 {
-                        str.push_str(", ");
-                    }
-                }
-                str.push_str("])");
-            }
-            Doc::Line => {
-                str.push_str("line");
-            }
-            Doc::Softline => {
-                str.push_str("softline");
-            }
-            Doc::Hardline => {
-                str.push_str("hardline");
-            }
-            Doc::IfBreak(break_contents) => {
-                str.push_str("ifBreak(");
-                str.push_str(&self.print(break_contents));
-                str.push(')');
-            }
-        }
-
-        str
-    }
-}
-
 #[derive(Clone, Copy)]
 #[allow(unused)]
 pub enum Separator {
@@ -146,3 +80,66 @@ impl<'a> Prettier<'a> {
         parts
     }
 }
+
+impl<'a> fmt::Display for Doc<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{})", print_do_to_debug(self))
+    }
+}
+
+// https://github.com/prettier/prettier/blob/main/src/document/debug.js
+fn print_do_to_debug(doc: &Doc<'_>) -> std::string::String {
+    use std::string::String;
+    let mut string = String::new();
+    match doc {
+        Doc::Str(s) => {
+            string.push('"');
+            string.push_str(s);
+            string.push('"');
+        }
+        Doc::Array(docs) => {
+            string.push_str("[\n");
+            for (idx, doc) in docs.iter().enumerate() {
+                string.push_str(&print_do_to_debug(doc));
+                if idx != docs.len() - 1 {
+                    string.push_str(", ");
+                }
+            }
+            string.push_str("]\n");
+        }
+        Doc::Indent(contents) => {
+            for (idx, doc) in contents.iter().enumerate() {
+                string.push_str(&print_do_to_debug(doc));
+                if idx != contents.len() - 1 {
+                    string.push_str(", ");
+                }
+            }
+        }
+        Doc::Group(contents) => {
+            string.push_str("group([\n");
+            for (idx, doc) in contents.iter().enumerate() {
+                string.push_str(&print_do_to_debug(doc));
+                if idx != contents.len() - 1 {
+                    string.push_str(", ");
+                }
+            }
+            string.push_str("])\n");
+        }
+        Doc::Line => {
+            string.push_str("line");
+        }
+        Doc::Softline => {
+            string.push_str("softline");
+        }
+        Doc::Hardline => {
+            string.push_str("hardline");
+        }
+        Doc::IfBreak(break_contents) => {
+            string.push_str("ifBreak(");
+            string.push_str(&print_do_to_debug(break_contents));
+            string.push(')');
+        }
+    }
+
+    string
+}

crates/oxc_prettier/src/lib.rs

@@ -16,7 +16,6 @@ use doc::Doc;
 use oxc_allocator::Allocator;
 use oxc_ast::{ast::Program, CommentKind, Trivias};
 
-pub use crate::doc::DocPrinter;
 pub use crate::options::{ArrowParens, EndOfLine, PrettierOptions, QuoteProps, TrailingComma};
 use crate::{format::Format, printer::Printer};
 

crates/oxc_wasm/src/lib.rs

@@ -14,7 +14,7 @@ use oxc::{
     transformer::{TransformOptions, TransformTarget, Transformer},
 };
 use oxc_linter::{LintContext, Linter};
-use oxc_prettier::{DocPrinter, Prettier, PrettierOptions};
+use oxc_prettier::{Prettier, PrettierOptions};
 use oxc_query::{schema, Adapter, SCHEMA_TEXT};
 use oxc_type_synthesis::{synthesize_program, Diagnostic as TypeCheckDiagnostic};
 use serde::Serialize;
@@ -196,8 +196,7 @@ impl Oxc {
             Prettier::new(&allocator, source_text, trivias.clone(), PrettierOptions::default())
                 .doc(program);
 
-        let mut doc_printer = DocPrinter::new(&allocator);
-        self.prettier_ir = format!("{}", doc_printer.print(&prettier_doc));
+        self.prettier_ir = prettier_doc.to_string();
 
         if run_options.syntax() && !run_options.lint() {
             let semantic_ret = SemanticBuilder::new(source_text, source_type)