Merge pull request #9253 from heinrich5991/pr_ddnet_contributing_if_int

Document that using integers in boolean contexts is not recommended

CONTRIBUTING.md

@@ -30,17 +30,17 @@ With the exception of base/system.{h,cpp}
 
 For single words
 
-- `int length = 0;` :x:
-- `int Length = 0;` :white_check_mark:
+- `int length = 0;` ❌
+- `int Length = 0;` ✅
 
 For multiple words:
 
-- `int maxLength = 0;` :x:
-- `int MaxLength = 0;` :white_check_mark:
+- `int maxLength = 0;` ❌
+- `int MaxLength = 0;` ✅
 
 ### Variable names should be descriptive
 
-:x: Avoid:
+❌ Avoid:
 
 ```C++
 for(int i = 0; i < MAX_CLIENTS; i++)
@@ -55,7 +55,7 @@ for(int i = 0; i < MAX_CLIENTS; i++)
 }
 ```
 
-:white_check_mark: Instead do:
+✅ Instead do:
 
 ```C++
 for(int ClientId = 0; ClientId < MAX_CLIENTS; ClientId++)
@@ -133,14 +133,14 @@ Do not use the `goto` keyword in new code, there are better control flow constru
 
 Do not set variables in if statements.
 
-:x:
+❌
 
 ```C++
 int Foo;
 if((Foo = 2)) { .. }
 ```
 
-:white_check_mark:
+✅
 
 ```C++
 int Foo = 2;
@@ -149,6 +149,22 @@ if(Foo) { .. }
 
 Unless the alternative code is more complex and harder to read.
 
+### Using integers in boolean contexts should be avoided
+
+❌
+
+```C++
+int Foo = 0;
+if(!Foo) { .. }
+```
+
+✅
+
+```C++
+int Foo = 0;
+if(Foo != 0) { .. }
+```
+
 ### Methods with default arguments should be avoided
 
 Default arguments tend to break quickly, if you have multiple you have to specify each even if you only want to change the last one.
@@ -161,13 +177,13 @@ Try finding descriptive names instead.
 
 While the code base already has a lot of methods that start with a ``Get`` prefix. If new getters are added they should not contain a prefix.
 
-:x:
+❌
 
 ```C++
 int GetMyVariable() { return m_MyVariable; }
 ```
 
-:white_check_mark:
+✅
 
 ```C++
 int MyVariable() { return m_MyVariable; }
@@ -175,7 +191,7 @@ int MyVariable() { return m_MyVariable; }
 
 ### Class member variables should be initialized where they are declared
 
-Instead of doing this :x::
+Instead of doing this ❌:
 
 ```C++
 class CFoo
@@ -184,7 +200,7 @@ class CFoo
 };
 ```
 
-Do this instead if possible :white_check_mark::
+Do this instead if possible ✅:
 
 ```C++
 class CFoo
@@ -211,17 +227,17 @@ Use `bool` instead. And `true` means success and `false` means failure.
 
 See https://github.com/ddnet/ddnet/issues/6436
 
-### filenames
+### Filenames
 
 Code file names should be all lowercase and words should be separated with underscores.
 
-:x:
+❌
 
 ```C++
 src/game/FooBar.cpp
 ```
 
-:white_check_mark:
+✅
 
 ```C++
 src/game/foo_bar.cpp