Add support for JSON with python3 -m json.tool

CHANGELOG.md

@@ -3,6 +3,13 @@
 All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog].
 
+## Unreleased
+
+### Formatters
+
+* [`python3-json`](https://docs.python.org/3/library/json.html#module-json.tool)
+  for JSON ([#257]).
+
 ## 4.0 (released 2023-11-23)
 ### Breaking changes
 * The order of entries in `apheleia-mode-alist` is no longer as

apheleia-formatters.el

@@ -133,6 +133,9 @@
         "--parser=yaml"
         (apheleia-formatters-js-indent "--use-tabs" "--tab-width")))
     (purs-tidy . ("apheleia-npx" "purs-tidy" "format"))
+    (python3-json
+     . ("python3" "-m" "json.tool"
+        (apheleia-formatters-js-indent "--tab" "--indent")))
     (rubocop . ("rubocop" "--stdin" filepath "--auto-correct"
                 "--stderr" "--format" "quiet" "--fail-level" "fatal"))
     (ruby-standard . ("standardrb" "--stdin" filepath "--fix" "--stderr"

apheleia-utils.el

@@ -49,6 +49,7 @@ INDENT-FLAG."
      (js2-mode 'js2-basic-offset)
      (js2-jsx-mode 'js2-basic-offset)
      (js3-mode 'js3-indent-level)
+     (python-mode 'python-indent-offset)
      (tsx-ts-mode 'typescript-ts-mode-indent-offset)
      (typescript-mode 'typescript-indent-level)
      (typescript-ts-mode 'typescript-ts-mode-indent-offset))))

test/formatters/installers/python3-json.bash

@@ -0,0 +1 @@
+apt-get install -y python3

test/formatters/samplecode/python3-json/in.json

@@ -0,0 +1 @@
+../prettier-json/in.json

test/formatters/samplecode/python3-json/out.json

@@ -0,0 +1,19 @@
+{
+    "arrowParens": "always",
+    "bracketSpacing": true,
+    "embeddedLanguageFormatting": "auto",
+    "htmlWhitespaceSensitivity": "css",
+    "insertPragma": false,
+    "jsxBracketSameLine": false,
+    "jsxSingleQuote": false,
+    "printWidth": 80,
+    "proseWrap": "preserve",
+    "quoteProps": "as-needed",
+    "requirePragma": false,
+    "semi": true,
+    "singleQuote": false,
+    "tabWidth": 2,
+    "trailingComma": "es5",
+    "useTabs": false,
+    "vueIndentScriptAndStyle": false
+}