Add rule for @ tokens (#106)

* Add rule for '@' tokens

* 0.7.1

* Bump mo-fmt

package.json

@@ -1,6 +1,6 @@
 {
     "name": "prettier-plugin-motoko",
-    "version": "0.7.0",
+    "version": "0.7.1",
     "description": "A code formatter for the Motoko smart contract language.",
     "main": "lib/environments/node.js",
     "browser": "lib/environments/web.js",

packages/mo-fmt/package.json

@@ -1,6 +1,6 @@
 {
     "name": "mo-fmt",
-    "version": "0.7.0",
+    "version": "0.7.1",
     "description": "An easy-to-use Motoko formatter command.",
     "main": "src/cli.js",
     "bin": {
@@ -22,7 +22,7 @@
         "commander": "^9.4.0",
         "fast-glob": "^3.2.11",
         "prettier": "^3.0",
-        "prettier-plugin-motoko": "^0.7.0"
+        "prettier-plugin-motoko": "^0.7.1"
     },
     "devDependencies": {
         "@rollup/plugin-commonjs": "^22.0.2",

src/printers/motoko-tt-ast/spaceConfig.ts

@@ -188,6 +188,9 @@ const spaceConfig: SpaceConfig = {
             'keep',
         ],
 
+        // misc
+        [tokenEquals('@'), '_', 'keep'],
+
         // default
         ['_', '_', 'space'],
     ],

tests/formatter.test.ts

@@ -414,6 +414,10 @@ describe('Motoko formatter', () => {
         );
     });
 
+    test('@ symbol', async () => {
+        expect(await format('@abc')).toStrictEqual('@abc\n');
+    });
+
     test('multi-line text', async () => {
         await expectFormatted('"A\nB"\n');
         await expectFormatted('"  A\n  B"\n');