Fix corner case with if-then expression (#83)

* Fix corner case with if-then expression

* 0.3.2

* Bump mo-fmt

package.json

@@ -1,6 +1,6 @@
 {
     "name": "prettier-plugin-motoko",
-    "version": "0.3.1",
+    "version": "0.3.2",
     "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": "0.3.1",
+    "version": "0.3.2",
     "description": "An easy-to-use Motoko formatter command.",
     "main": "src/cli.js",
     "bin": {
@@ -21,7 +21,7 @@
         "commander": "^9.4.0",
         "fast-glob": "^3.2.11",
         "prettier": "^2.7",
-        "prettier-plugin-motoko": "^0.3.1"
+        "prettier-plugin-motoko": "^0.3.2"
     },
     "devDependencies": {
         "@rollup/plugin-commonjs": "^22.0.2",

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

@@ -124,6 +124,9 @@ const spaceConfig: SpaceConfig = {
         ['Delim', '_', 'line'],
         // ['Delim', 'Line', 'nil'],
 
+        // if-then expressions
+        [{ left: tokenEquals('if'), main: '_' }, 'Paren', 'space'],
+
         // unary operators
         [tokenEquals('#'), 'Ident', 'keep'],
         [tokenEquals('+'), '_', 'keep'],

tests/formatter.test.ts

@@ -322,6 +322,13 @@ describe('Motoko formatter', () => {
         expect(format('{\n// }\n}\nA\n')).toStrictEqual('{\n  // }\n};\nA;\n');
     });
 
+    test('conditional parentheses', () => {
+        expect(format('if a b')).toStrictEqual('if a b\n');
+        expect(format('if (a) b')).toStrictEqual('if (a) b\n');
+        expect(format('if a (b)')).toStrictEqual('if a (b)\n');
+        expect(format('if (a) (b)')).toStrictEqual('if (a) (b)\n');
+    });
+
     // test('generate diff files from compiler tests', () => {
     //     for (const extension of ['mo', 'did']) {
     //         let preOutput = '';