Add methods inheritance

src/main/fr/celticinfo/lox/LoxClass.kt

@@ -12,8 +12,14 @@ class LoxClass(private val name: String, private val superClass: LoxClass?, priv
     }
 
     fun findMethod(name: String): LoxFunction? {
+        if (methods.containsKey(name)) {
             return methods[name]
         }
+        if (superClass != null) {
+            return superClass.findMethod(name)
+        }
+        return null
+    }
 
     override fun arity() = findMethod("init")?.arity() ?: 0
 

src/test/fr/celticinfo/lox/InterpreterTest.kt

@@ -989,4 +989,41 @@ var a = "global";
             System.setOut(standardOut)
         }
     }
+
+    @Test
+    fun `Inheriting a method should work`() {
+        val standardOut = System.out
+        val outputStreamCaptor = ByteArrayOutputStream()
+
+        System.setOut(PrintStream(outputStreamCaptor))
+
+        try {
+            val code = """
+                class Doughnut {
+                  cook() {
+                    print "Fry until golden brown.";
+                  }
+                }
+                
+                class BostonCream < Doughnut {}
+                
+                BostonCream().cook();
+            """.trimIndent()
+            val scanner = Scanner(code)
+            val tokens = scanner.scanTokens()
+            val parser = Parser(tokens)
+            val statements = parser.parse()
+            assertEquals(3, statements.size)
+
+            val interpreter = Interpreter()
+
+            val resolver = Resolver(interpreter)
+            resolver.resolve(statements)
+
+            interpreter.interpret(statements)
+            val output = outputStreamCaptor.toString().trim()
+            assertEquals("Fry until golden brown.", output)
+        } finally {
+            System.setOut(standardOut)
         }
+    }}