Short aswer for explain how type self in actions and etc.

[akaguny]

My English is not good, but i want improve docs =)
What about transformation documentation section about typescript to troubleshooting with ready to use recipes with short answers?
Anyway i want to see in documentation variant without this and managing of multiply views =)
Pls help with it if you agree)

Index: docs/tips/typescript.md
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- docs/tips/typescript.md	(revision 8f3706d08e35f600d12a658ae1ecb19a12f85638)
+++ docs/tips/typescript.md	(date 1607213900937)
@@ -68,6 +68,29 @@
 
 #### Typing `self` in actions and views
 
+You can help typescript with manually type self:
+
+```typescript
+const Todo = types
+    .model({
+        title: "hello"
+    })
+    .actions((self: ITodo) => ({
+        get upperProp(): string {
+            return self.prop.toUpperCase()
+        },
+        get twiceUpperProp(): string {
+            return self.upperProp + self.upperProp // Compile error: `self.upperProp` is not yet defined
+        }
+    }))
+
+interface ITodo extends Instance<typeof Todo> {}
+interface ITodoSnapshotIn extends SnapshotIn<typeof Todo> {}
+interface ITodoSnapshotOut extends SnapshotOut<typeof Todo> {}
+```
+
+Explain the problem:
+
 The type of `self` is what `self` was **before the action or views blocks starts**, and only after that part finishes, the actions will be added to the type of `self`.
 
 Sometimes you'll need to take into account where your typings are available and where they aren't. The code below will not compile: TypeScript will complain that `self.upperProp` is not a known property. Computed properties are only available after `.views` is evaluated.
@@ -111,7 +134,7 @@
     get upperProp(): string {
       return self.prop.toUpperCase();
     },
-  }))
+  })
   .views(self => ({
     get twiceUpperProp(): string {
       return self.upperProp + self.upperProp;
@@ -134,7 +157,7 @@
         }
       }
       return views
-  }))
+  })

NOTE: the last approach will incur runtime performance penalty as accessing such computed values (e.g. inside render() method of an observed component) always leads to full recompute (see this issue for details). For a heavily used computed properties it's recommended to use one of above approaches.

[akaguny]

reference to itself, typescript will crash =((