fix: failed to parsing ternary statement in some error cases, #483

Author: killme2008

src/main/java/com/googlecode/aviator/lexer/ExpressionLexer.java

@@ -442,7 +442,11 @@ public Token<?> scan(final boolean analyse) {
   }
 
   public String getScanString() {
-    return this.expression.substring(0, this.iterator.getIndex());
+    Token<?> firstPushbackToken = this.tokenBuffer != null ? this.tokenBuffer.peekFirst() : null;
+    return this.expression.substring(0,
+        (firstPushbackToken != null && firstPushbackToken.getStartIndex() > 0)
+            ? firstPushbackToken.getEndIndex()
+            : this.iterator.getIndex());
   }
 
   private String getBigNumberLexeme(final StringBuilder sb) {

src/main/java/com/googlecode/aviator/lexer/token/AbstractToken.java

@@ -107,6 +107,11 @@ public int getStartIndex() {
     return this.lineIndex;
   }
 
+  @Override
+  public int getEndIndex() {
+    return this.lineIndex + (this.lexeme != null ? this.lexeme.length() : 0);
+  }
+
 
   @Override
   public String toString() {

src/main/java/com/googlecode/aviator/lexer/token/Token.java

@@ -48,5 +48,7 @@ enum TokenType {
 
   int getStartIndex();
 
+  int getEndIndex();
+
   int getLineNo();
 }

src/main/java/com/googlecode/aviator/parser/ExpressionParser.java

@@ -1051,7 +1051,7 @@ private void pattern() {
     this.inPattern = true;
     StringBuilder sb = new StringBuilder();
     while (this.lookhead != null) {
-      while (!expectChar('/')) {
+      while (!expectChar('/') && this.lookhead != null) {
         sb.append(this.lookhead.getLexeme());
         move(false);
       }
@@ -1886,6 +1886,16 @@ private StatementType statements() {
       ensureDepthState();
     }
     ensureNoStatementAfterReturn(stmtType);
+    // If the last statement is ternary,it must be ended with END TOKEN such as null token, '}',
+    // 'end' keyword, or ';'
+    // Otherwise report syntax error.
+    if (stmtType == StatementType.Ternary) {
+      if (lookhead != null && !expectChar(';') && !expectChar('}') && lookhead != Variable.END) {
+        this.back();
+        reportSyntaxError("unexpect token '" + currentTokenLexeme()
+            + "', maybe forget to insert ';' to complete last expression ");
+      }
+    }
 
     return stmtType;
   }

src/test/java/com/googlecode/aviator/test/function/GrammarUnitTest.java

@@ -143,6 +143,23 @@ public void testCompareWithVariableSyntaxSuger() {
     assertTrue((boolean) this.instance.execute("data == nil"));
   }
 
+  @Test
+  public void testIssue483() {
+    try {
+      this.instance
+          .execute("if(true){\n" + "return false;\n" + "}\n" + "//注释xxxx\n" + "return true;");
+      fail();
+    } catch (ExpressionSyntaxErrorException e) {
+    }
+
+    try {
+      this.instance.execute("if(true){\n" + "return false;\n" + "}\n" + "//\n" + "return true;");
+      fail();
+    } catch (ExpressionSyntaxErrorException e) {
+      e.printStackTrace();
+    }
+  }
+
   @Test
   public void testEscapeStringInterpolation() {
     this.instance.disableFeature(Feature.StringInterpolation);