Add ui test of lint

Author: cocodery

tests/ui/might_panic.fixed

@@ -0,0 +1,18 @@
+#![allow(clippy::might_panic)]
+
+fn main() {
+    // declare 2 array to access
+    let arr1 = &[1, 2, 3];
+    let arr2 = &[[1], [2], [3]];
+
+    // trigger `might-panic` lint
+    // with and without explicit type declaration
+    let Some(_num1) = arr1.get(1) else { panic!() };
+    let Some(_num2): Option<&i32> = arr1.get(5) else { panic!() };
+
+    let Some(_num3) = arr2.get(1) else { panic!() };
+    let Some(_num4): Option<&[i32; 1]> = arr2.get(5) else { panic!() };
+
+    // not trigger `might-panic` lint
+    let _num5 = arr2[0][0];
+}

tests/ui/might_panic.rs

@@ -0,0 +1,18 @@
+#![allow(clippy::might_panic)]
+
+fn main() {
+    // declare 2 array to access
+    let arr1 = &[1, 2, 3];
+    let arr2 = &[[1], [2], [3]];
+
+    // trigger `might-panic` lint
+    // with and without explicit type declaration
+    let _num1 = arr1[1]; // warning
+    let _num2: i32 = arr1[5]; // warning
+
+    let _num3 = arr2[1]; // warning
+    let _num4: [i32; 1] = arr2[5]; // warning
+
+    // not trigger `might-panic` lint
+    let _num5 = arr2[0][0]; // no warning
+}

tests/ui/might_panic.stderr

@@ -0,0 +1,34 @@
+warning: use `get()` function if you're not sure whether index is legal
+ --> src/main.rs:8:5
+  |
+8 |     let _num1 = arr1[1];
+  |     ^^^^^^^^^^^^^^^^^^^^ help: Try: `let Some(_num1) = arr1.get(1) else { panic!() };`
+  |
+  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#might_panic
+  = note: `#[warn(clippy::might_panic)]` on by default
+
+warning: use `get()` function if you're not sure whether index is legal
+ --> src/main.rs:9:5
+  |
+9 |     let _num2: i32 = arr1[5];
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: Try: `let Some(_num2): Option<&i32> = arr1.get(5) else { panic!() };`
+  |
+  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#might_panic
+
+warning: use `get()` function if you're not sure whether index is legal
+  --> src/main.rs:11:5
+   |
+11 |     let _num3 = arr2[1];
+   |     ^^^^^^^^^^^^^^^^^^^^ help: Try: `let Some(_num3) = arr2.get(1) else { panic!() };`
+   |
+   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#might_panic
+
+warning: use `get()` function if you're not sure whether index is legal
+  --> src/main.rs:12:5
+   |
+12 |     let _num4: [i32; 1] = arr2[5];
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Try: `let Some(_num4): Option<&[i32; 1]> = arr2.get(5) else { panic!() };`
+   |
+   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#might_panic
+
+warning: `src` (bin "src") generated 4 warnings (run `cargo clippy --fix --bin "src"` to apply 4 suggestions)