1 files changed, 158 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/same_item_push.rs b/src/tools/clippy/tests/ui/same_item_push.rs
new file mode 100644
index 000000000..99964f0de
--- /dev/null
+++ b/src/tools/clippy/tests/ui/same_item_push.rs
@@ -0,0 +1,158 @@
+#![warn(clippy::same_item_push)]
+
+const VALUE: u8 = 7;
+
+fn mutate_increment(x: &mut u8) -> u8 {
+    *x += 1;
+    *x
+}
+
+fn increment(x: u8) -> u8 {
+    x + 1
+}
+
+fn fun() -> usize {
+    42
+}
+
+fn main() {
+    // ** linted cases **
+    let mut vec: Vec<u8> = Vec::new();
+    let item = 2;
+    for _ in 5..=20 {
+        vec.push(item);
+    }
+
+    let mut vec: Vec<u8> = Vec::new();
+    for _ in 0..15 {
+        let item = 2;
+        vec.push(item);
+    }
+
+    let mut vec: Vec<u8> = Vec::new();
+    for _ in 0..15 {
+        vec.push(13);
+    }
+
+    let mut vec = Vec::new();
+    for _ in 0..20 {
+        vec.push(VALUE);
+    }
+
+    let mut vec = Vec::new();
+    let item = VALUE;
+    for _ in 0..20 {
+        vec.push(item);
+    }
+
+    // ** non-linted cases **
+    let mut spaces = Vec::with_capacity(10);
+    for _ in 0..10 {
+        spaces.push(vec![b' ']);
+    }
+
+    // Suggestion should not be given as pushed variable can mutate
+    let mut vec: Vec<u8> = Vec::new();
+    let mut item: u8 = 2;
+    for _ in 0..30 {
+        vec.push(mutate_increment(&mut item));
+    }
+
+    let mut vec: Vec<u8> = Vec::new();
+    let mut item: u8 = 2;
+    let mut item2 = &mut mutate_increment(&mut item);
+    for _ in 0..30 {
+        vec.push(mutate_increment(item2));
+    }
+
+    let mut vec: Vec<usize> = Vec::new();
+    for (a, b) in [0, 1, 4, 9, 16].iter().enumerate() {
+        vec.push(a);
+    }
+
+    let mut vec: Vec<u8> = Vec::new();
+    for i in 0..30 {
+        vec.push(increment(i));
+    }
+
+    let mut vec: Vec<u8> = Vec::new();
+    for i in 0..30 {
+        vec.push(i + i * i);
+    }
+
+    // Suggestion should not be given as there are multiple pushes that are not the same
+    let mut vec: Vec<u8> = Vec::new();
+    let item: u8 = 2;
+    for _ in 0..30 {
+        vec.push(item);
+        vec.push(item * 2);
+    }
+
+    // Suggestion should not be given as Vec is not involved
+    for _ in 0..5 {
+        println!("Same Item Push");
+    }
+
+    struct A {
+        kind: u32,
+    }
+    let mut vec_a: Vec<A> = Vec::new();
+    for i in 0..30 {
+        vec_a.push(A { kind: i });
+    }
+    let mut vec: Vec<u8> = Vec::new();
+    for a in vec_a {
+        vec.push(2u8.pow(a.kind));
+    }
+
+    // Fix #5902
+    let mut vec: Vec<u8> = Vec::new();
+    let mut item = 0;
+    for _ in 0..10 {
+        vec.push(item);
+        item += 10;
+    }
+
+    // Fix #5979
+    let mut vec: Vec<std::fs::File> = Vec::new();
+    for _ in 0..10 {
+        vec.push(std::fs::File::open("foobar").unwrap());
+    }
+    // Fix #5979
+    #[derive(Clone)]
+    struct S;
+
+    trait T {}
+    impl T for S {}
+
+    let mut vec: Vec<Box<dyn T>> = Vec::new();
+    for _ in 0..10 {
+        vec.push(Box::new(S {}));
+    }
+
+    // Fix #5985
+    let mut vec = Vec::new();
+    let item = 42;
+    let item = fun();
+    for _ in 0..20 {
+        vec.push(item);
+    }
+
+    // Fix #5985
+    let mut vec = Vec::new();
+    let key = 1;
+    for _ in 0..20 {
+        let item = match key {
+            1 => 10,
+            _ => 0,
+        };
+        vec.push(item);
+    }
+
+    // Fix #6987
+    let mut vec = Vec::new();
+    for _ in 0..10 {
+        vec.push(1);
+        vec.extend(&[2]);
+    }
+}