Fix block comment parsing

src/main/scanner.ts

@@ -308,45 +308,36 @@ export function createScanner(
     function multilineComment(): void {
         let comment: string = ''
         let cursor: number = 0
+        let isNewLine = true
 
-        while (true) {
-            if (
-                current() === '\n' ||
-                isAtEnd() ||
-                (current() !== '/' && current() !== '*' && current() !== ' ')
-            ) {
-                break
-            } else {
-                advance()
-            }
-        }
+        // Skip first two characters: '/' and '*'
+        advance()
+        advance()
 
         while (true) {
-            if (current() === '\n') {
-                nextLine()
+            // A comment goes until we find a comment terminator (*/).
+            if ((current() === '*' && peek() === '/') || isAtEnd()) {
+                advance()
+                break
             }
 
-            if (
-                comment.charAt(cursor - 1) === '\n' &&
-                (peek() === ' ' || peek() === '*')
-            ) {
+            if (isNewLine && (current() === ' ' || current() === '*')) {
                 /**
                  * We ignore stars and spaces after a new line to normalize comment formatting.
                  * We're only keeping the text of the comment without the extranious formatting.
                  */
             } else {
+                isNewLine = false
                 comment += current()
                 cursor += 1
             }
 
-            advance()
-
-            // A comment goes until we find a comment terminator (*/).
-            if ((peek() === '*' && peekNext() === '/') || isAtEnd()) {
-                advance()
-                advance()
-                break
+            if (current() === '\n') {
+                isNewLine = true
+                nextLine()
             }
+
+            advance()
         }
 
         addToken(SyntaxType.CommentBlock, comment.trim())

src/tests/parser/fixtures/empty-comments.thrift

@@ -0,0 +1,14 @@
+//
+/* */
+/** */
+/*
+ *
+ */
+/**
+ *
+ */
+/*
+ */
+/**
+ */
+const string test = 'test'

src/tests/parser/parser.spec.ts

@@ -21,6 +21,14 @@ function loadSolution(name: string): object {
     )
 }
 
+function saveSolution(fileName: string, obj: any) {
+    fs.writeFileSync(
+        path.join(__dirname, `./solutions/${fileName}.solution.json`),
+        JSON.stringify(obj, null, 4),
+        'utf-8',
+    )
+}
+
 function objectify(thrift: ThriftDocument): object {
     return JSON.parse(JSON.stringify(thrift))
 }
@@ -414,6 +422,19 @@ describe('Parser', () => {
         assert.deepEqual(objectify(thrift), expected)
     })
 
+    it('should correctly handle empty block comments', () => {
+        const content: string = loadSource('empty-comments')
+        const scanner: Scanner = createScanner(content)
+        const tokens: Array<Token> = scanner.scan()
+
+        const parser: Parser = createParser(tokens)
+        const thrift: ThriftDocument = parser.parse()
+
+        const expected: any = loadSolution('empty-comments')
+
+        assert.deepEqual(objectify(thrift), expected)
+    })
+
     it('should correctly parse annotations', () => {
         const content: string = loadSource('annotations')
         const scanner: Scanner = createScanner(content)