Fix accidental removal of trailing newline (#170)

This plugin began removing the trailing newline from files as of v3.
This was caused by an accidental removal of the "root" AST node, which
was introduced by Prettier v3. The parse has been updated to preserve
this node, which in turn preserves the trailing newline.

Fixes #168

src/index.test.ts

@@ -151,13 +151,14 @@ test('should throw if custom sort has invalid category sort values', async (t) =
 
 for (const validJson of validJsonExamples) {
   test(`should return '${validJson}' unchanged`, async (t) => {
-    const output = await format(validJson, {
+    const validJsonWithNewline = `${validJson}\n`;
+    const output = await format(validJsonWithNewline, {
       filepath: 'foo.json',
       parser: 'json',
       plugins: [SortJsonPlugin],
     });
 
-    t.is(output, validJson);
+    t.is(output, validJsonWithNewline);
   });
 }
 

src/index.test.ts.md

@@ -20,7 +20,8 @@ Generated by [AVA](https://avajs.dev).
         "a": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should sort an unsorted JSON object
 
@@ -38,7 +39,8 @@ Generated by [AVA](https://avajs.dev).
         "a": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should validate a sorted JSON object recursively
 
@@ -55,7 +57,8 @@ Generated by [AVA](https://avajs.dev).
         "z": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should sort an unsorted JSON object recursively
 
@@ -72,7 +75,8 @@ Generated by [AVA](https://avajs.dev).
         "z": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should validate a sorted JSON object within an array recursively
 
@@ -94,7 +98,8 @@ Generated by [AVA](https://avajs.dev).
         "z": null␊
       },␊
       2␊
-    ]`
+    ]␊
+    `
 
 ## should sort an unsorted JSON object within an array recursively
 
@@ -116,7 +121,8 @@ Generated by [AVA](https://avajs.dev).
         "z": null␊
       },␊
       2␊
-    ]`
+    ]␊
+    `
 
 ## should validate a deeply nested sorted JSON object recursively
 
@@ -142,7 +148,8 @@ Generated by [AVA](https://avajs.dev).
         "z": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should sort an unsorted deeply nested JSON object recursively
 
@@ -168,7 +175,8 @@ Generated by [AVA](https://avajs.dev).
         "z": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should validate a sorted JSON object with unconventional keys
 
@@ -204,7 +212,8 @@ Generated by [AVA](https://avajs.dev).
       "{": null,␊
       "{}": null,␊
       "￿": null␊
-    }`
+    }␊
+    `
 
 ## should sort a JSON object with unconventional keys
 
@@ -240,7 +249,8 @@ Generated by [AVA](https://avajs.dev).
       "{": null,␊
       "{}": null,␊
       "￿": null␊
-    }`
+    }␊
+    `
 
 ## should sort JSON objects recursively within a nested array
 
@@ -268,7 +278,8 @@ Generated by [AVA](https://avajs.dev).
         }␊
       ],␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should validate JSON objects recursively within a nested array
 
@@ -296,7 +307,8 @@ Generated by [AVA](https://avajs.dev).
         }␊
       ],␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should validate a sorted JSON object with a simple custom sort
 
@@ -314,7 +326,8 @@ Generated by [AVA](https://avajs.dev).
         "a": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should sort an unsorted JSON object with a simple custom sort
 
@@ -332,7 +345,8 @@ Generated by [AVA](https://avajs.dev).
         "a": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should validate a sorted JSON object with a numeric custom sort
 
@@ -356,7 +370,8 @@ Generated by [AVA](https://avajs.dev).
       },␊
       "first": "first",␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should sort an unsorted JSON object with a numeric custom sort
 
@@ -380,7 +395,8 @@ Generated by [AVA](https://avajs.dev).
       },␊
       "first": "first",␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should validate a sorted JSON object with a complex custom sort
 
@@ -427,7 +443,8 @@ Generated by [AVA](https://avajs.dev).
         "a": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `
 
 ## should sort an unsorted JSON object with a complex custom sort
 
@@ -472,4 +489,5 @@ Generated by [AVA](https://avajs.dev).
         "050": null␊
       },␊
       "z": null␊
-    }`
+    }␊
+    `

src/index.ts

@@ -195,7 +195,7 @@ export const parsers = {
           (ast.type === 'ArrayExpression' && jsonRecursiveSort)
         )
       ) {
-        return ast;
+        return jsonRootAst;
       }
 
       let sortCompareFunction: (a: string, b: string) => number = lexicalSort;
@@ -272,7 +272,12 @@ export const parsers = {
           return aIndex - bIndex;
         };
       }
-      return sortAst(ast, jsonRecursiveSort, sortCompareFunction);
+      const sortedAst = sortAst(ast, jsonRecursiveSort, sortCompareFunction);
+
+      return {
+        ...jsonRootAst,
+        node: sortedAst,
+      };
     },
   },
 } as Record<string, Parser>;