Added error when Enum member initaliser references itself (microsoft#34655)

Fixes microsoft#34606

Author: acutmore

src/compiler/checker.ts

@@ -33764,6 +33764,9 @@ namespace ts {
                         error(expr, Diagnostics.A_member_initializer_in_a_enum_declaration_cannot_reference_members_declared_after_it_including_members_defined_in_other_enums);
                         return 0;
                     }
+                    else {
+                        error(expr, Diagnostics.Property_0_is_used_before_being_assigned, symbolToString(memberSymbol));
+                    }
                 }
                 return undefined;
             }

tests/baselines/reference/enumPropertyAccessBeforeInitalisation.errors.txt

@@ -0,0 +1,22 @@
+tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts(2,9): error TS2565: Property 'A' is used before being assigned.
+tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts(3,9): error TS2565: Property 'B' is used before being assigned.
+tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts(4,9): error TS2565: Property 'C' is used before being assigned.
+tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts(5,13): error TS2565: Property 'D' is used before being assigned.
+
+
+==== tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts (4 errors) ====
+    enum E {
+        A = A,
+            ~
+!!! error TS2565: Property 'A' is used before being assigned.
+        B = E.B,
+            ~~~
+!!! error TS2565: Property 'B' is used before being assigned.
+        C = E["C"],
+            ~~~~~~
+!!! error TS2565: Property 'C' is used before being assigned.
+        D = 1 + D
+                ~
+!!! error TS2565: Property 'D' is used before being assigned.
+    }
+    

tests/baselines/reference/enumPropertyAccessBeforeInitalisation.js

@@ -0,0 +1,17 @@
+//// [enumPropertyAccessBeforeInitalisation.ts]
+enum E {
+    A = A,
+    B = E.B,
+    C = E["C"],
+    D = 1 + D
+}
+
+
+//// [enumPropertyAccessBeforeInitalisation.js]
+var E;
+(function (E) {
+    E[E["A"] = E.A] = "A";
+    E[E["B"] = E.B] = "B";
+    E[E["C"] = E["C"]] = "C";
+    E[E["D"] = 1 + E.D] = "D";
+})(E || (E = {}));

tests/baselines/reference/enumPropertyAccessBeforeInitalisation.symbols

@@ -0,0 +1,24 @@
+=== tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts ===
+enum E {
+>E : Symbol(E, Decl(enumPropertyAccessBeforeInitalisation.ts, 0, 0))
+
+    A = A,
+>A : Symbol(E.A, Decl(enumPropertyAccessBeforeInitalisation.ts, 0, 8))
+>A : Symbol(E.A, Decl(enumPropertyAccessBeforeInitalisation.ts, 0, 8))
+
+    B = E.B,
+>B : Symbol(E.B, Decl(enumPropertyAccessBeforeInitalisation.ts, 1, 10))
+>E.B : Symbol(E.B, Decl(enumPropertyAccessBeforeInitalisation.ts, 1, 10))
+>E : Symbol(E, Decl(enumPropertyAccessBeforeInitalisation.ts, 0, 0))
+>B : Symbol(E.B, Decl(enumPropertyAccessBeforeInitalisation.ts, 1, 10))
+
+    C = E["C"],
+>C : Symbol(E.C, Decl(enumPropertyAccessBeforeInitalisation.ts, 2, 12))
+>E : Symbol(E, Decl(enumPropertyAccessBeforeInitalisation.ts, 0, 0))
+>"C" : Symbol(E.C, Decl(enumPropertyAccessBeforeInitalisation.ts, 2, 12))
+
+    D = 1 + D
+>D : Symbol(E.D, Decl(enumPropertyAccessBeforeInitalisation.ts, 3, 15))
+>D : Symbol(E.D, Decl(enumPropertyAccessBeforeInitalisation.ts, 3, 15))
+}
+

tests/baselines/reference/enumPropertyAccessBeforeInitalisation.types

@@ -0,0 +1,27 @@
+=== tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts ===
+enum E {
+>E : E
+
+    A = A,
+>A : E
+>A : E
+
+    B = E.B,
+>B : E
+>E.B : E
+>E : typeof E
+>B : E
+
+    C = E["C"],
+>C : E
+>E["C"] : E
+>E : typeof E
+>"C" : "C"
+
+    D = 1 + D
+>D : E
+>1 + D : number
+>1 : 1
+>D : E
+}
+

tests/cases/compiler/enumPropertyAccessBeforeInitalisation.ts

@@ -0,0 +1,6 @@
+enum E {
+    A = A,
+    B = E.B,
+    C = E["C"],
+    D = 1 + D
+}