feat: add json(c) support to deno fmt (#9292)

This commit adds support for formatting JSON and JSONC 
in "deno fmt".

New values "json" and "jsonc" are added to "--ext" flag for 
standard input processing.

1 files changed, 45 insertions, 12 deletions

diff --git a/cli/tools/fmt.rs b/cli/tools/fmt.rs
index 61875d172..d4002984a 100644
--- a/cli/tools/fmt.rs
+++ b/cli/tools/fmt.rs
@@ -10,7 +10,7 @@
 use crate::colors;
 use crate::diff::diff;
 use crate::file_watcher;
-use crate::fs_util::{collect_files, get_extension, is_supported_ext_md};
+use crate::fs_util::{collect_files, get_extension, is_supported_ext_fmt};
 use crate::text_encoding;
 use deno_core::error::generic_error;
 use deno_core::error::AnyError;
@@ -37,7 +37,7 @@ pub async fn format(
 ) -> Result<(), AnyError> {
   let target_file_resolver = || {
     // collect the files that are to be formatted
-    collect_files(&args, &ignore, is_supported_ext_md)
+    collect_files(&args, &ignore, is_supported_ext_fmt)
   };
   let operation = |paths: Vec<PathBuf>| {
     let config = get_typescript_config();
@@ -75,7 +75,14 @@ fn format_markdown(
       let tag = tag.to_lowercase();
       if matches!(
         tag.as_str(),
-        "ts" | "tsx" | "js" | "jsx" | "javascript" | "typescript"
+        "ts"
+          | "tsx"
+          | "js"
+          | "jsx"
+          | "javascript"
+          | "typescript"
+          | "json"
+          | "jsonc"
       ) {
         // It's important to tell dprint proper file extension, otherwise
         // it might parse the file twice.
@@ -84,16 +91,22 @@ fn format_markdown(
           "typescript" => "ts",
           rest => rest,
         };
-        let fake_filename =
-          PathBuf::from(format!("deno_fmt_stdin.{}", extension));
 
-        let mut codeblock_config = ts_config.clone();
-        codeblock_config.line_width = line_width;
-        dprint_plugin_typescript::format_text(
-          &fake_filename,
-          &text,
-          &codeblock_config,
-        )
+        if matches!(extension, "json" | "jsonc") {
+          let mut json_config = get_json_config();
+          json_config.line_width = line_width;
+          dprint_plugin_json::format_text(&text, &json_config)
+        } else {
+          let fake_filename =
+            PathBuf::from(format!("deno_fmt_stdin.{}", extension));
+          let mut codeblock_config = ts_config.clone();
+          codeblock_config.line_width = line_width;
+          dprint_plugin_typescript::format_text(
+            &fake_filename,
+            &text,
+            &codeblock_config,
+          )
+        }
       } else {
         Ok(text.to_string())
       }
@@ -101,6 +114,14 @@ fn format_markdown(
   )
 }
 
+/// Formats JSON and JSONC using the rules provided by .deno()
+/// of configuration builder of https://github.com/dprint/dprint-plugin-json.
+/// See https://git.io/Jt4ht for configuration.
+fn format_json(file_text: &str) -> Result<String, String> {
+  let json_config = get_json_config();
+  dprint_plugin_json::format_text(&file_text, &json_config)
+}
+
 async fn check_source_files(
   config: dprint_plugin_typescript::configuration::Configuration,
   paths: Vec<PathBuf>,
@@ -120,6 +141,8 @@ async fn check_source_files(
       let ext = get_extension(&file_path).unwrap_or_else(String::new);
       let r = if ext == "md" {
         format_markdown(&file_text, config.clone())
+      } else if matches!(ext.as_str(), "json" | "jsonc") {
+        format_json(&file_text)
       } else {
         dprint_plugin_typescript::format_text(&file_path, &file_text, &config)
       };
@@ -179,6 +202,8 @@ async fn format_source_files(
       let ext = get_extension(&file_path).unwrap_or_else(String::new);
       let r = if ext == "md" {
         format_markdown(&file_contents.text, config.clone())
+      } else if matches!(ext.as_str(), "json" | "jsonc") {
+        format_json(&file_contents.text)
       } else {
         dprint_plugin_typescript::format_text(
           &file_path,
@@ -240,6 +265,8 @@ pub fn format_stdin(check: bool, ext: String) -> Result<(), AnyError> {
   let config = get_typescript_config();
   let r = if ext.as_str() == "md" {
     format_markdown(&source, config)
+  } else if matches!(ext.as_str(), "json" | "jsonc") {
+    format_json(&source)
   } else {
     // dprint will fallback to jsx parsing if parsing this as a .ts file doesn't work
     dprint_plugin_typescript::format_text(
@@ -291,6 +318,12 @@ fn get_markdown_config() -> dprint_plugin_markdown::configuration::Configuration
     .build()
 }
 
+fn get_json_config() -> dprint_plugin_json::configuration::Configuration {
+  dprint_plugin_json::configuration::ConfigurationBuilder::new()
+    .deno()
+    .build()
+}
+
 struct FileContents {
   text: String,
   had_bom: bool,