16 incr decr incrby decrby

src/main/java/org/fungover/haze/Command.java

@@ -1,5 +1,5 @@
 package org.fungover.haze;
 
 public enum Command {
-    SET, GET, DEL, PING, SETNX, EXISTS, SAVE, RPUSH, LPUSH, LPOP, RPOP, LLEN, LMOVE, LTRIM, AUTH
+    SET, GET, DEL, PING, SETNX, EXISTS, SAVE, RPUSH, LPUSH, LPOP, RPOP, LLEN, LMOVE, LTRIM, AUTH, INCR, DECR
 }

src/main/java/org/fungover/haze/HazeDatabase.java

@@ -143,4 +143,47 @@ public void addValue(String key, String value) {
             lock.unlock();
         }
     }
+
+    public String increaseValue(List<String> inputList) {
+        lock.lock();
+        String key = inputList.get(1);
+        try {
+            if (!database.containsKey(key)) {
+                return "-ERR no such key\r\n";
+            }
+            String value = database.get(key);
+            try {
+                long longValue = Long.parseLong(value);
+                longValue++;
+                database.put(key, String.valueOf(longValue));
+                return ":" + longValue + "\r\n";
+            } catch (NumberFormatException e) {
+                return "-WRONGTYPE value is not an integer or out of range\r\n";
+            }
+        } finally {
+            lock.unlock();
+        }
+    }
+
+    public String decreaseValue(List<String> inputList) {
+        lock.lock();
+        String key = inputList.get(1);
+        try {
+            if (!database.containsKey(key)) {
+                return "-ERR no such key\r\n";
+            }
+            String value = database.get(key);
+            try {
+                long longValue = Long.parseLong(value);
+                longValue--;
+                database.put(key, String.valueOf(longValue));
+                return ":" + longValue + "\r\n";
+            } catch (NumberFormatException e) {
+                return "-WRONGTYPE value is not an integer or out of range\r\n";
+            }
+        } finally {
+            lock.unlock();
+        }
+    }
+
 }

src/main/java/org/fungover/haze/Main.java

@@ -121,7 +121,8 @@ public static String executeCommand(HazeDatabase hazeDatabase, List<String> inpu
             case LMOVE -> hazeList.lMove(inputList);
             case LTRIM -> hazeList.callLtrim(inputList);
             case AUTH -> "+OK\r\n";
-
+            case INCR -> hazeDatabase.increaseValue(inputList);
+            case DECR -> hazeDatabase.decreaseValue(inputList);
         };
     }
 

src/test/java/org/fungover/haze/HazeDatabaseTest.java

@@ -159,5 +159,31 @@ void shouldShouldReturnTrue(){
         assertThat(testDatabase.containsKey("key1")).isTrue();
     }
 
+    @Test
+    void callingIncreaseWithKeyWithIntegerShouldIncreaseValueBy1(){
+        testDatabase.addValue("key1", "1");
+
+        String increaseResult = testDatabase.increaseValue(List.of("INCR","key1"));
+        assertThat(increaseResult).isEqualTo(":2\r\n");
+        assertThat(testDatabase.getValue("key1")).isEqualTo("2");
+
+    }
+
+    @Test
+    void callingIncreaseWithKeyThatDoesNotContainIntegerShouldReturnErrorMessage() {
+        testDatabase.addValue("key1", "Gunnar");
+        String increaseResult = testDatabase.increaseValue(List.of("INCR","key1"));
+        assertThat(increaseResult).isEqualTo("-WRONGTYPE value is not an integer or out of range\r\n");
+    }
+    @Test
+    void callingDecreaseWithKeyWithIntegerShouldDecreaseValueBy1(){
+        testDatabase.addValue("key1", "1");
+
+        String increaseResult = testDatabase.decreaseValue(List.of("DECR","key1"));
+        assertThat(increaseResult).isEqualTo(":0\r\n");
+        assertThat(testDatabase.getValue("key1")).isEqualTo("0");
+
+    }
+
 
 }

src/test/java/org/fungover/haze/MainTest.java

@@ -108,6 +108,18 @@ void callExecuteCommandWithLTRIMShouldReturnErrorMessageWhenKeyDoesNotExist() {
         assertThat(Main.executeCommand(database, List.of("LTRIM", "key", "2", "3"), hazeList)).isEqualTo("-The key is not present in the database.\r\n");
     }
 
+    @Test
+    void callExecuteCommandWithIncrShouldIncreaseTheValueOfTheKeyBy1() {
+        Main.executeCommand(database, List.of("SET", "key1", "1"), hazeList);
+        assertThat(Main.executeCommand(database, List.of("INCR", "key1"), hazeList)).isEqualTo(":2\r\n");
+    }
+
+    @Test
+    void callExecuteCommandWithDecrShouldDecreaseTheValueOfTheKeyBy1(){
+        Main.executeCommand(database, List.of("SET", "key1", "1"), hazeList);
+        assertThat(Main.executeCommand(database, List.of("DECR", "key1"), hazeList)).isEqualTo(":0\r\n");
+    }
+
     @Test
     void testPrintThreadDebug() {
         ByteArrayOutputStream outContent = new ByteArrayOutputStream();