refactor(BREAKING): external formatter accepts string instead of MediaType (#723)

Author: bartlomieju

src/format_text.rs

@@ -159,8 +159,8 @@ mod test {
       extension: None,
       text: "const content = html`<div>broken html</p>`".into(),
       config: &config,
-      external_formatter: Some(&|media_type, _text, _config| {
-        assert!(matches!(media_type, deno_ast::MediaType::Html));
+      external_formatter: Some(&|lang, _text, _config| {
+        assert!(matches!(lang, "html"));
         Err(anyhow::anyhow!("Syntax error from external formatter"))
       }),
     });

src/generation/context.rs

@@ -18,9 +18,10 @@ use super::*;
 use crate::configuration::*;
 use crate::utils::Stack;
 
-/// A callback that will be called when encountering certain tagged templates.
+/// A callback that will be called when encountering tagged templates.
 ///
-/// Currently supports `css`, `html` and `sql` tagged templated.
+/// It is up to the caller to decide if a certain tagged template should be formatted
+/// by the external formatter.
 ///
 /// Examples:
 /// ```ignore
@@ -41,11 +42,11 @@ use crate::utils::Stack;
 ///   active IS TRUE;
 /// ```
 ///
-/// External formatter should return `None` if it doesn't understand given `MediaType`, in such
+/// External formatter should return `None` if it doesn't understand given language, in such
 /// cases the templates will be left as they are.
 ///
 /// Only templates with no interpolation are supported.
-pub type ExternalFormatter = dyn Fn(MediaType, String, &Configuration) -> anyhow::Result<Option<String>>;
+pub type ExternalFormatter = dyn Fn(&str, String, &Configuration) -> anyhow::Result<Option<String>>;
 
 pub(crate) struct GenerateDiagnostic {
   pub message: String,

src/generation/generate.rs

@@ -3016,13 +3016,13 @@ fn gen_spread_element<'a>(node: &SpreadElement<'a>, context: &mut Context<'a>) -
 /// Detects the type of embedded language automatically.
 fn maybe_gen_tagged_tpl_with_external_formatter<'a>(node: &TaggedTpl<'a>, context: &mut Context<'a>) -> Option<PrintItems> {
   let external_formatter = context.external_formatter.as_ref()?;
-  let media_type = detect_embedded_language_type(node)?;
+  let embedded_lang = normalize_embedded_language_type(node)?;
 
   let placeholder_css = "@dpr1nt_";
   let placeholder_other = "dpr1nt_";
   // First creates text with placeholders for the expressions.
-  let placeholder_text = match media_type {
-    MediaType::Css => placeholder_css,
+  let placeholder_text = match embedded_lang {
+    "css" => placeholder_css,
     _ => placeholder_other,
   };
   let text = capacity_builder::StringBuilder::<String>::build(|builder| {
@@ -3043,7 +3043,7 @@ fn maybe_gen_tagged_tpl_with_external_formatter<'a>(node: &TaggedTpl<'a>, contex
   .unwrap();
 
   // Then formats the text with the external formatter.
-  let formatted_tpl = match external_formatter(media_type, text.replace(r"\\", "\\"), context.config) {
+  let formatted_tpl = match external_formatter(embedded_lang, text.replace(r"\\", "\\"), context.config) {
     Ok(formatted_tpl) => formatted_tpl?.replace("\\", r"\\"),
     Err(err) => {
       context.diagnostics.push(context::GenerateDiagnostic {
@@ -3102,29 +3102,22 @@ fn maybe_gen_tagged_tpl_with_external_formatter<'a>(node: &TaggedTpl<'a>, contex
   Some(items)
 }
 
-/// Detects the type of embedded language in a tagged template literal.
-fn detect_embedded_language_type<'a>(node: &TaggedTpl<'a>) -> Option<MediaType> {
+/// Normalizes the type of embedded language in a tagged template literal.
+fn normalize_embedded_language_type<'a>(node: &TaggedTpl<'a>) -> Option<&'a str> {
   match node.tag {
-    Expr::Ident(ident) => {
-      match ident.sym().as_str() {
-        "css" => Some(MediaType::Css),   // css`...`
-        "html" => Some(MediaType::Html), // html`...`
-        "sql" => Some(MediaType::Sql),   // sql`...`
-        _ => None,
-      }
-    }
+    Expr::Ident(ident) => return Some(ident.sym().as_str()),
     Expr::Member(member_expr) => {
       if let Expr::Ident(ident) = member_expr.obj {
         if ident.sym().as_str() == "styled" {
-          return Some(MediaType::Css); // styled.foo`...`
+          return Some("css"); // styled.foo`...`
         }
       }
       None
     }
     Expr::Call(call_expr) => {
       if let Callee::Expr(Expr::Ident(ident)) = call_expr.callee {
         if ident.sym().as_str() == "styled" {
-          return Some(MediaType::Css); // styled(Button)`...`
+          return Some("css"); // styled(Button)`...`
         }
       }
       None

tests/spec_test.rs

@@ -2,18 +2,17 @@ use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 use anyhow::Result;
-use deno_ast::MediaType;
 use dprint_core::configuration::*;
 use dprint_development::*;
 use dprint_plugin_typescript::configuration::*;
 use dprint_plugin_typescript::*;
 
-fn external_formatter(media_type: MediaType, text: String, config: &Configuration) -> Result<Option<String>> {
-  match media_type {
-    MediaType::Css => format_embedded_css(&text, config),
-    MediaType::Html => format_html(&text, config),
-    MediaType::Sql => format_sql(&text, config),
-    _ => unreachable!(),
+fn external_formatter(lang: &str, text: String, config: &Configuration) -> Result<Option<String>> {
+  match lang {
+    "css" => format_embedded_css(&text, config),
+    "html" => format_html(&text, config),
+    "sql" => format_sql(&text, config),
+    _ => Ok(None),
   }
 }