Add tag directive tests

ballerina/tests/parse_string_negative.bal

@@ -40,3 +40,22 @@ function negativeDataProvider() returns [string, string][] => [
         "'block mapping cannot have the same indent as a block sequence' at line: '3' column: '10'"
     ]
 ];
+
+@test:Config {
+    dataProvider: tagHandleNegativeDataProvider
+}
+isolated function tagHandleNegativeTests(string path, string expectedErrMsg) returns io:Error? {
+    string fullPath = NEGATIVE_TEST_PATH + "tag_handle_negative/" + path;
+    string content = check io:fileReadString(fullPath);
+    anydata|Error result = parseString(content);
+    test:assertTrue(result is Error);
+    test:assertEquals((<Error>result).message(), expectedErrMsg);
+}
+
+function tagHandleNegativeDataProvider() returns [string, string][] => [
+    ["tag_handle_negative_1.yaml", "'incompatible yaml version for the 1.2 parser' at line: '1' column: '9'"],
+    ["tag_handle_negative_2.yaml", "'incompatible yaml version for the 1.2 parser' at line: '1' column: '9'"],
+    ["tag_handle_negative_3.yaml", "'YAML document version is already defined' at line: '2' column: '5'"],
+    ["tag_handle_negative_4.yaml", "'duplicate tag handle' at line: '2' column: '12'"],
+    ["tag_handle_negative_5.yaml", "'custom tags not supported' at line: '1' column: '28'"]
+];

ballerina/tests/parser_tests.bal

@@ -32,7 +32,11 @@ isolated function testTagHandles(string inputPath, TestCase expectedValue) retur
 function tagHandleData() returns [string, TestCase][] => [
     ["tag_handle_1.yaml", {case: "uri_scanner"}],
     ["tag_handle_2.yaml", {case: "yaml_version"}],
-    ["tag_handle_3.yaml", {case: "verbitam"}]
+    ["tag_handle_3.yaml", {case: "verbitam"}],
+    ["tag_handle_4.yaml", {case: "yaml_version"}],
+    ["tag_handle_5.yaml", {case: "yaml_version"}],
+    ["tag_handle_6.yaml", {case: "reserved directive"}],
+    ["tag_handle_7.yaml", {case: "secondary tag handle"}]
 ];
 
 type TestCase record {|

ballerina/tests/resources/negative/tag_handle_negative/tag_handle_negative_1.yaml

@@ -0,0 +1,3 @@
+%YAML 2.1
+---
+case: "yaml_version"

ballerina/tests/resources/negative/tag_handle_negative/tag_handle_negative_2.yaml

@@ -0,0 +1,3 @@
+%YAML 0.1
+---
+case: "yaml_version"

ballerina/tests/resources/negative/tag_handle_negative/tag_handle_negative_3.yaml

@@ -0,0 +1,4 @@
+%YAML 1.2
+%YAML 1.1
+---
+case: "yaml_version"

ballerina/tests/resources/negative/tag_handle_negative/tag_handle_negative_4.yaml

@@ -0,0 +1,4 @@
+%TAG !yaml! tag:yaml.org,2002:
+%TAG !yaml! tag:yaml.org,2002:
+---
+name:  !yaml!str user

ballerina/tests/resources/negative/tag_handle_negative/tag_handle_negative_5.yaml

@@ -0,0 +1,3 @@
+%TAG ! tag:example.com,2000:
+---
+name:  !!str user

ballerina/tests/resources/parser/tag_handle_1.yaml

@@ -1,3 +1,3 @@
-%TAG ! tag:example.com,2002:
+%TAG ! tag:yaml.org,2002:
 ---
 case: uri_scanner

ballerina/tests/resources/parser/tag_handle_4.yaml

@@ -0,0 +1,3 @@
+%YAML 1.1
+---
+case: "yaml_version"

ballerina/tests/resources/parser/tag_handle_5.yaml

@@ -0,0 +1,3 @@
+%YAML 1.3
+---
+case: "yaml_version"

ballerina/tests/resources/parser/tag_handle_6.yaml

@@ -0,0 +1,3 @@
+%FOO  bar baz
+--- 
+case: reserved directive

ballerina/tests/resources/parser/tag_handle_7.yaml

@@ -0,0 +1,3 @@
+%TAG !! tag:yaml.org,2002:
+---
+case:  !!str secondary tag handle

native/src/main/java/io/ballerina/lib/data/yaml/lexer/Scanner.java

@@ -291,8 +291,7 @@ public boolean scan(LexerState sm) throws Error.YamlParserException {
 
             // Scan the word of the name tag.
             if (matchPattern(sm, List.of(WORD_PATTERN, URI_PATTERN),
-                    List.of(new Utils.CharPattern('!'), FLOW_INDICATOR_PATTERN), 1)) {
-                sm.forward();
+                    List.of(new Utils.CharPattern('!'), FLOW_INDICATOR_PATTERN), 0)) {
                 sm.appendToLexeme(Character.toString(sm.peek()));
                 // Store the complete primary tag if another '!' cannot be detected.
                 if (differentiate && sm.peek(1) == -1) {
@@ -304,22 +303,20 @@ public boolean scan(LexerState sm) throws Error.YamlParserException {
             }
 
             // Scan the end delimiter of the tag.
-            if (sm.peek(1) == '!') {
-                sm.forward();
+            if (sm.peek() == '!') {
                 sm.appendToLexeme("!");
                 return true;
             }
 
             // Store the complete primary tag if a white space or a flow indicator is detected.
-            if (differentiate && matchPattern(sm, List.of(FLOW_INDICATOR_PATTERN, WHITE_SPACE_PATTERN), 1)) {
+            if (differentiate && matchPattern(sm, List.of(FLOW_INDICATOR_PATTERN, WHITE_SPACE_PATTERN), 0)) {
                 sm.setLexemeBuffer(sm.getLexeme().substring(1));
                 sm.setLexeme("!");
                 return true;
             }
 
             // Store the complete primary tag if a hexadecimal escape is detected.
-            if (differentiate && sm.peek(1) == '%') {
-                sm.forward();
+            if (differentiate && sm.peek() == '%') {
                 scanUnicodeEscapedCharacters(sm, '%', 2);
                 sm.setLexemeBuffer(sm.getLexeme().substring(1));
                 sm.setLexeme("!");

native/src/main/java/io/ballerina/lib/data/yaml/parser/Directive.java

@@ -21,6 +21,7 @@
 
 import io.ballerina.lib.data.yaml.lexer.LexerState;
 import io.ballerina.lib.data.yaml.lexer.Token;
+import io.ballerina.lib.data.yaml.utils.Constants;
 import io.ballerina.lib.data.yaml.utils.Error;
 
 import java.util.List;
@@ -90,6 +91,10 @@ public static void tagDirective(ParserState state) throws Error.YamlParserExcept
         YamlParser.getNextToken(state, List.of(Token.TokenType.TAG_PREFIX));
         String tagPrefix = state.getCurrentToken().getValue();
 
+        if (!tagPrefix.equals(Constants.DEFAULT_GLOBAL_TAG_HANDLE)) {
+            throw new Error.YamlParserException("custom tags not supported", state.getLine(), state.getColumn());
+        }
+
         state.getCustomTagHandles().put(tagHandle, tagPrefix);
     }
 
@@ -108,9 +113,6 @@ public static void reservedDirective(ParserState state) throws Error.YamlParserE
         while (state.getBufferedToken().getType() == Token.TokenType.SEPARATION_IN_LINE) {
             YamlParser.getNextToken(state);
             YamlParser.getNextToken(state, true);
-            if (state.getBufferedToken().getType() != Token.TokenType.PRINTABLE_CHAR) {
-                break;
-            }
             YamlParser.getNextToken(state);
             reservedDirective.append(" ").append(state.getCurrentToken().getValue());
             YamlParser.getNextToken(state, true);