Check existence of option key

Author: silverbullettt

src/main/java/pascal/taie/config/AnalysisOptions.java

@@ -74,7 +74,23 @@ void update(AnalysisOptions options) {
         this.options.putAll(options.options);
     }
 
+    /**
+     * @return {@code true} if this AnalysisOptions contains value
+     * for given option key.
+     */
+    public boolean has(String key) {
+        return options.containsKey(key);
+    }
+
+    /**
+     * @return value for given option key.
+     * @throws ConfigException if this AnalysisOptions do not contain the key.
+     */
     public Object get(String key) {
+        if (!has(key)) {
+            throw new ConfigException("Cannot find option '" + key + "'," +
+                    " please check your configuration and option key");
+        }
         return options.get(key);
     }
 

src/test/java/pascal/taie/config/AnalysisOptionsTest.java

@@ -0,0 +1,52 @@
+/*
+ * Tai-e: A Static Analysis Framework for Java
+ *
+ * Copyright (C) 2022 Tian Tan <tiantan@nju.edu.cn>
+ * Copyright (C) 2022 Yue Li <yueli@nju.edu.cn>
+ *
+ * This file is part of Tai-e.
+ *
+ * Tai-e is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation, either version 3
+ * of the License, or (at your option) any later version.
+ *
+ * Tai-e is distributed in the hope that it will be useful,but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Tai-e. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package pascal.taie.config;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class AnalysisOptionsTest {
+
+    @Test
+    public void testNullOption() {
+        AnalysisOptions options = new AnalysisOptions(getOptionValues());
+        Assert.assertNull(options.get("z"));
+    }
+
+    @Test(expected = ConfigException.class)
+    public void testNonExistOption() {
+        AnalysisOptions options = new AnalysisOptions(getOptionValues());
+        options.get("non-exist-key");
+    }
+
+    private Map<String, Object> getOptionValues() {
+        Map<String, Object> values = new HashMap<>();
+        values.put("x", 100);
+        values.put("y", "666");
+        values.put("z", null);
+        return values;
+    }
+}