Fix else/else if parsing when on new line after closing brace

Add 'else' to scanner's multiline statement detection, matching 'and'
handling

Author: nojaf

src/scanner.c

@@ -243,6 +243,18 @@ bool tree_sitter_rescript_external_scanner_scan(
           in_multiline_statement = true;
         }
       }
+    } else if (lexer->lookahead == 'e') {
+      advance(lexer);
+      if (lexer->lookahead == 'l') {
+        advance(lexer);
+        if (lexer->lookahead == 's') {
+          advance(lexer);
+          if (lexer->lookahead == 'e') {
+            // Ignore new lines before `else` keyword (else/else if clauses)
+            in_multiline_statement = true;
+          }
+        }
+      }
     }
 
     if (in_multiline_statement) {

test/corpus/expressions.txt

@@ -479,6 +479,66 @@ if predicateA {
           (expression_statement
             (value_identifier)))))))
 
+================================================================================
+If/else with else on new line
+================================================================================
+
+if predicateA {
+  foo
+}
+else if predicateB {
+  bar
+}
+else {
+  baz
+}
+
+if predicateA {
+  foo
+} // comment before else if
+else if predicateB {
+  bar
+} // comment before else
+else {
+  baz
+}
+
+--------------------------------------------------------------------------------
+
+(source_file
+  (expression_statement
+    (if_expression
+      (value_identifier)
+      (block
+        (expression_statement
+          (value_identifier)))
+      (else_if_clause
+        (value_identifier)
+        (block
+          (expression_statement
+            (value_identifier))))
+      (else_clause
+        (block
+          (expression_statement
+            (value_identifier))))))
+  (expression_statement
+    (if_expression
+      (value_identifier)
+      (block
+        (expression_statement
+          (value_identifier)))
+      (comment)
+      (else_if_clause
+        (value_identifier)
+        (block
+          (expression_statement
+            (value_identifier))))
+      (comment)
+      (else_clause
+        (block
+          (expression_statement
+            (value_identifier)))))))
+
 ================================================================================
 Switch of literals
 ================================================================================
@@ -1639,7 +1699,7 @@ try for i in 0 to 10 {
   call()
 } catch {
 | Not_found => false
-} 
+}
 
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