[trac4269] Add unit tests and move the parse code to the right place

src/lib/eval/parser.yy

@@ -131,11 +131,6 @@ bool_expr : "(" bool_expr ")"
                        error(@1, "relay4 can only be used in DHCPv4.");
                    }
                 }
-          | PKT6 "." pkt6_field
-                {
-                    TokenPtr pkt6field(new TokenPkt6($3));
-                    ctx.expression.push_back(pkt6field);
-                }
           ;
 
 string_expr : STRING
@@ -183,6 +178,11 @@ string_expr : STRING
                       TokenPtr conc(new TokenConcat());
                       ctx.expression.push_back(conc);
                   }
+            | PKT6 "." pkt6_field
+                  {
+                      TokenPtr pkt6field(new TokenPkt6($3));
+                      ctx.expression.push_back(pkt6field);
+                  }
             ;
 
 option_code : INTEGER

src/lib/eval/tests/context_unittest.cc

@@ -123,6 +123,20 @@ public:
         EXPECT_TRUE(conc);
     }
 
+    /// @brief checks if the given token is Pkt6 of specified type
+    /// @param token token to be checked
+    /// @param type expected type of the Pkt6 field
+    void checkTokenPkt6(const TokenPtr& token, TokenPkt6::FieldType type) {
+        ASSERT_TRUE(token);
+
+        boost::shared_ptr<TokenPkt6> pkt =
+            boost::dynamic_pointer_cast<TokenPkt6>(token);
+
+        ASSERT_TRUE(pkt);
+
+        EXPECT_EQ(type, pkt->getType());
+    }
+
     /// @brief checks if the given expression raises the expected message
     /// when it is parsed.
     void checkError(const string& expr, const string& msg) {
@@ -147,6 +161,38 @@ public:
         universe_ = universe;
     }
 
+    /// @brief Test that verifies access to the DHCPv6 packet fields.
+    ///
+    /// This test attempts to parse the expression, will check if the number
+    /// of tokens is exactly as planned and then will try to verify if the
+    /// first token represents expected the field in DHCPv6 packet.
+    ///
+    /// @param expr expression to be parsed
+    /// @param exp_type expected field type to be parsed
+    /// @param exp_tokens expected number of tokens
+    void testPkt6Field(std::string expr, TokenPkt6::FieldType exp_type,
+                       int exp_tokens) {
+        EvalContext eval(Option::V6);
+
+        // Parse the expression.
+        try {
+            parsed_ = eval.parseString(expr);
+        }
+        catch (const EvalParseError& ex) {
+            FAIL() << "Exception thrown: " << ex.what();
+            return;
+        }
+
+        // Parsing should succeed and return a token.
+        EXPECT_TRUE(parsed_);
+
+        // There should be the requested number of tokens
+        ASSERT_EQ(exp_tokens, eval.expression.size());
+
+        // Check that the first token is TokenPkt6 instance and has correct type.
+        checkTokenPkt6(eval.expression.at(0), exp_type);
+    }
+
     Option::Universe universe_;
     bool parsed_; ///< Parsing status
 };
@@ -334,6 +380,16 @@ TEST_F(EvalContextTest, relay4Error) {
                "<string>:1.1-6: relay4 can only be used in DHCPv4.");
 }
 
+// Tests whether message type field in DHCPv6 can be accessed.
+TEST_F(EvalContextTest, pkt6FieldMsgtype) {
+    testPkt6Field("pkt6.msgtype == '1'", TokenPkt6::MSGTYPE, 3);
+}
+
+// Tests whether transaction id field in DHCPv6 can be accessed.
+TEST_F(EvalContextTest, pkt6FieldTransid) {
+    testPkt6Field("pkt6.transid == '1'", TokenPkt6::TRANSID, 3);
+}
+
 // Test parsing of logical operators
 TEST_F(EvalContextTest, logicalOps) {
     // option.exists

src/lib/eval/tests/token_unittest.cc

@@ -967,3 +967,22 @@ TEST_F(TokenTest, concat) {
     ASSERT_EQ(1, values_.size());
     EXPECT_EQ("foobar", values_.top());
 }
+
+// Verifies if the DHCPv6 packet fields can be extracted.
+TEST_F(TokenTest, pkt6Fields) {
+    // The default test creates a v6 DHCPV6_SOLICIT packet with a
+    // transaction id of 12345.
+
+    // Check the message type
+    ASSERT_NO_THROW(t_.reset(new TokenPkt6(TokenPkt6::MSGTYPE)));
+    EXPECT_NO_THROW(t_->evaluate(*pkt6_, values_));
+    ASSERT_EQ(1, values_.size());
+    EXPECT_EQ("1", values_.top());
+
+    // Check the transaction id field
+    clearStack();
+    ASSERT_NO_THROW(t_.reset(new TokenPkt6(TokenPkt6::TRANSID)));
+    EXPECT_NO_THROW(t_->evaluate(*pkt6_, values_));
+    ASSERT_EQ(1, values_.size());
+    EXPECT_EQ("12345", values_.top());
+}