1 files changed, 214 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/implicit_saturating_sub.rs b/src/tools/clippy/tests/ui/implicit_saturating_sub.rs
new file mode 100644
index 000000000..8bb28d149
--- /dev/null
+++ b/src/tools/clippy/tests/ui/implicit_saturating_sub.rs
@@ -0,0 +1,214 @@
+// run-rustfix
+#![allow(unused_assignments, unused_mut, clippy::assign_op_pattern)]
+#![warn(clippy::implicit_saturating_sub)]
+
+fn main() {
+    // Tests for unsigned integers
+
+    let end_8: u8 = 10;
+    let start_8: u8 = 5;
+    let mut u_8: u8 = end_8 - start_8;
+
+    // Lint
+    if u_8 > 0 {
+        u_8 = u_8 - 1;
+    }
+
+    match end_8 {
+        10 => {
+            // Lint
+            if u_8 > 0 {
+                u_8 -= 1;
+            }
+        },
+        11 => u_8 += 1,
+        _ => u_8 = 0,
+    }
+
+    let end_16: u16 = 40;
+    let start_16: u16 = 35;
+
+    let mut u_16: u16 = end_16 - start_16;
+
+    // Lint
+    if u_16 > 0 {
+        u_16 -= 1;
+    }
+
+    let mut end_32: u32 = 7010;
+    let mut start_32: u32 = 7000;
+
+    let mut u_32: u32 = end_32 - start_32;
+
+    // Lint
+    if u_32 != 0 {
+        u_32 -= 1;
+    }
+
+    // No Lint
+    if u_32 > 0 {
+        u_16 += 1;
+    }
+
+    // No Lint
+    if u_32 != 0 {
+        end_32 -= 1;
+        start_32 += 1;
+    }
+
+    let mut end_64: u64 = 75001;
+    let mut start_64: u64 = 75000;
+
+    let mut u_64: u64 = end_64 - start_64;
+
+    // Lint
+    if u_64 > 0 {
+        u_64 -= 1;
+    }
+
+    // Lint
+    if 0 < u_64 {
+        u_64 -= 1;
+    }
+
+    // Lint
+    if 0 != u_64 {
+        u_64 -= 1;
+    }
+
+    // No Lint
+    if u_64 >= 1 {
+        u_64 -= 1;
+    }
+
+    // No Lint
+    if u_64 > 0 {
+        end_64 -= 1;
+    }
+
+    // Tests for usize
+    let end_usize: usize = 8054;
+    let start_usize: usize = 8050;
+
+    let mut u_usize: usize = end_usize - start_usize;
+
+    // Lint
+    if u_usize > 0 {
+        u_usize -= 1;
+    }
+
+    // Tests for signed integers
+
+    let endi_8: i8 = 10;
+    let starti_8: i8 = 50;
+
+    let mut i_8: i8 = endi_8 - starti_8;
+
+    // Lint
+    if i_8 > i8::MIN {
+        i_8 -= 1;
+    }
+
+    // Lint
+    if i_8 > i8::MIN {
+        i_8 -= 1;
+    }
+
+    // Lint
+    if i_8 != i8::MIN {
+        i_8 -= 1;
+    }
+
+    // Lint
+    if i_8 != i8::MIN {
+        i_8 -= 1;
+    }
+
+    let endi_16: i16 = 45;
+    let starti_16: i16 = 44;
+
+    let mut i_16: i16 = endi_16 - starti_16;
+
+    // Lint
+    if i_16 > i16::MIN {
+        i_16 -= 1;
+    }
+
+    // Lint
+    if i_16 > i16::MIN {
+        i_16 -= 1;
+    }
+
+    // Lint
+    if i_16 != i16::MIN {
+        i_16 -= 1;
+    }
+
+    // Lint
+    if i_16 != i16::MIN {
+        i_16 -= 1;
+    }
+
+    let endi_32: i32 = 45;
+    let starti_32: i32 = 44;
+
+    let mut i_32: i32 = endi_32 - starti_32;
+
+    // Lint
+    if i_32 > i32::MIN {
+        i_32 -= 1;
+    }
+
+    // Lint
+    if i_32 > i32::MIN {
+        i_32 -= 1;
+    }
+
+    // Lint
+    if i_32 != i32::MIN {
+        i_32 -= 1;
+    }
+
+    // Lint
+    if i_32 != i32::MIN {
+        i_32 -= 1;
+    }
+
+    let endi_64: i64 = 45;
+    let starti_64: i64 = 44;
+
+    let mut i_64: i64 = endi_64 - starti_64;
+
+    // Lint
+    if i64::MIN < i_64 {
+        i_64 -= 1;
+    }
+
+    // Lint
+    if i64::MIN != i_64 {
+        i_64 -= 1;
+    }
+
+    // Lint
+    if i64::MIN < i_64 {
+        i_64 -= 1;
+    }
+
+    // No Lint
+    if i_64 > 0 {
+        i_64 -= 1;
+    }
+
+    // No Lint
+    if i_64 != 0 {
+        i_64 -= 1;
+    }
+
+    // issue #7831
+    // No Lint
+    if u_32 > 0 {
+        u_32 -= 1;
+    } else {
+        println!("side effect");
+    }
+}