refactor(ast_tools): move JS file header creation (#6897)

Move creation of generated JS/TS file headers out of individual generators.

tasks/ast_tools/src/codegen.rs

@@ -61,7 +61,7 @@ impl From<GeneratorOutput> for SideEffect {
     fn from(output: GeneratorOutput) -> Self {
         match output {
             GeneratorOutput::Rust { path, tokens } => Self::from((path, tokens)),
-            GeneratorOutput::Text { path, content } => Self { path, content: content.into() },
+            GeneratorOutput::Javascript { path, code } => Self { path, content: code.into() },
         }
     }
 }
@@ -244,7 +244,7 @@ pub trait CodegenBase {
 }
 
 /// Creates a generated file warning + required information for a generated file.
-pub fn generate_header(file_path: &str) -> TokenStream {
+pub fn generate_rust_header(file_path: &str) -> TokenStream {
     let file_path = file_path.replace('\\', "/");
 
     // TODO: Add generation date, AST source hash, etc here.
@@ -255,3 +255,14 @@ pub fn generate_header(file_path: &str) -> TokenStream {
         //!@@line_break
     }
 }
+
+/// Creates a generated file warning + required information for a generated file.
+pub fn generate_javascript_header(file_path: &str) -> String {
+    let file_path = file_path.replace('\\', "/");
+
+    // TODO: Add generation date, AST source hash, etc here.
+    format!(
+        "// Auto-generated code, DO NOT EDIT DIRECTLY!\n\
+        // To edit this generated file you have to edit `{file_path}`\n\n"
+    )
+}

tasks/ast_tools/src/derives/mod.rs

@@ -6,7 +6,7 @@ use proc_macro2::TokenStream;
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
-    codegen::{generate_header, CodegenBase, LateCtx},
+    codegen::{generate_rust_header, CodegenBase, LateCtx},
     schema::TypeDef,
     Result,
 };
@@ -44,7 +44,7 @@ pub trait Derive: CodegenBase {
     // Standard methods
 
     fn template(module_paths: Vec<&str>, impls: TokenStream) -> TokenStream {
-        let header = generate_header(Self::file_path());
+        let header = generate_rust_header(Self::file_path());
         let prelude = Self::prelude();
 
         // from `x::y::z` to `crate::y::z::*`

tasks/ast_tools/src/generators/mod.rs

@@ -4,7 +4,7 @@ use proc_macro2::TokenStream;
 use quote::quote;
 
 use crate::{
-    codegen::{generate_header, CodegenBase, LateCtx},
+    codegen::{generate_javascript_header, generate_rust_header, CodegenBase, LateCtx},
     Result,
 };
 
@@ -23,7 +23,7 @@ pub use visit::{VisitGenerator, VisitMutGenerator};
 #[derive(Debug, Clone)]
 pub enum GeneratorOutput {
     Rust { path: PathBuf, tokens: TokenStream },
-    Text { path: PathBuf, content: String },
+    Javascript { path: PathBuf, code: String },
 }
 
 pub trait Generator: CodegenBase {
@@ -36,12 +36,18 @@ pub trait Generator: CodegenBase {
     fn output(&mut self, ctx: &LateCtx) -> Result<GeneratorOutput> {
         let mut output = self.generate(ctx);
 
-        if let GeneratorOutput::Rust { tokens, .. } = &mut output {
-            let header = generate_header(Self::file_path());
-            *tokens = quote! {
-                #header
-                #tokens
-            };
+        match &mut output {
+            GeneratorOutput::Rust { tokens, .. } => {
+                let header = generate_rust_header(Self::file_path());
+                *tokens = quote! {
+                    #header
+                    #tokens
+                };
+            }
+            GeneratorOutput::Javascript { code: content, .. } => {
+                let header = generate_javascript_header(Self::file_path());
+                *content = format!("{header}{content}");
+            }
         }
 
         Ok(output)

tasks/ast_tools/src/generators/typescript.rs

@@ -24,14 +24,7 @@ define_generator!(TypescriptGenerator);
 
 impl Generator for TypescriptGenerator {
     fn generate(&mut self, ctx: &LateCtx) -> GeneratorOutput {
-        let file = file!().replace('\\', "/");
-        let mut content = format!(
-            "\
-            // Auto-generated code, DO NOT EDIT DIRECTLY!\n\
-            // To edit this generated file you have to edit `{file}`\n\n\
-            {CUSTOM_TYPESCRIPT}\n\
-            "
-        );
+        let mut code = format!("{CUSTOM_TYPESCRIPT}\n");
 
         for def in ctx.schema() {
             if !def.generates_derive("ESTree") {
@@ -43,12 +36,13 @@ impl Generator for TypescriptGenerator {
             };
             let Some(ts_type_def) = ts_type_def else { continue };
 
-            content.push_str(&ts_type_def);
-            content.push_str("\n\n");
+            code.push_str(&ts_type_def);
+            code.push_str("\n\n");
         }
-        GeneratorOutput::Text {
+
+        GeneratorOutput::Javascript {
             path: output(crate::TYPESCRIPT_PACKAGE, "types.d.ts"),
-            content: format_typescript(&content),
+            code: format_typescript(&code),
         }
     }
 }