test: add trait cast test

Author: Chronostasys

src/ast/expects/trait_diag.pi.expect

@@ -602,6 +602,76 @@
             },
         },
     },
+    PLDiag {
+        raw: PLDiagRaw {
+            code: Err(
+                THE_TARGET_TRAIT_CANNOT_BE_INSTANTIATED,
+            ),
+            help: None,
+            labels: [
+                PLLabel {
+                    file: "",
+                    txt: Some(
+                        (
+                            "the method `{}` of trait `{}` has generic params, which makes it uninstantiatable",
+                            [
+                                "hash",
+                                "Hash",
+                            ],
+                        ),
+                    ),
+                    range: Range {
+                        start: Pos {
+                            line: 5,
+                            column: 5,
+                            offset: 99,
+                        },
+                        end: Pos {
+                            line: 5,
+                            column: 41,
+                            offset: 135,
+                        },
+                    },
+                },
+                PLLabel {
+                    file: "",
+                    txt: Some(
+                        (
+                            "trait type `{}`",
+                            [
+                                "Hash",
+                            ],
+                        ),
+                    ),
+                    range: Range {
+                        start: Pos {
+                            line: 124,
+                            column: 9,
+                            offset: 1811,
+                        },
+                        end: Pos {
+                            line: 124,
+                            column: 17,
+                            offset: 1819,
+                        },
+                    },
+                },
+            ],
+            source: None,
+            range: Range {
+                start: Pos {
+                    line: 124,
+                    column: 9,
+                    offset: 1811,
+                },
+                end: Pos {
+                    line: 124,
+                    column: 17,
+                    offset: 1819,
+                },
+            },
+        },
+    },
     PLDiag {
         raw: PLDiagRaw {
             code: Err(
@@ -612,14 +682,14 @@
             source: None,
             range: Range {
                 start: Pos {
-                    line: 172,
+                    line: 173,
                     column: 15,
-                    offset: 2446,
+                    offset: 2475,
                 },
                 end: Pos {
-                    line: 172,
+                    line: 173,
                     column: 17,
-                    offset: 2448,
+                    offset: 2477,
                 },
             },
         },
@@ -643,29 +713,29 @@
                     ),
                     range: Range {
                         start: Pos {
-                            line: 176,
+                            line: 177,
                             column: 6,
-                            offset: 2459,
+                            offset: 2488,
                         },
                         end: Pos {
-                            line: 176,
+                            line: 177,
                             column: 7,
-                            offset: 2460,
+                            offset: 2489,
                         },
                     },
                 },
             ],
             source: None,
             range: Range {
                 start: Pos {
-                    line: 176,
+                    line: 177,
                     column: 6,
-                    offset: 2459,
+                    offset: 2488,
                 },
                 end: Pos {
-                    line: 176,
+                    line: 177,
                     column: 7,
-                    offset: 2460,
+                    offset: 2489,
                 },
             },
         },

test/lsp_diag/trait_diag.pi

@@ -121,6 +121,7 @@ pub fn test_trait() void {
     st.call_trait();
     fn_with_trait(y);
     fn_with_trait(y);
+    let hashtest:Hash = "a";
     return;
 }
 

test/main.pi

@@ -96,7 +96,6 @@ pub fn main() i64 {
     let bbbb = 1;
     let re = ttt.eq(&bbbb);
     println!(re);
-    let hashtest:Hash = "a";
     return 0;
 }