Added few more tests and other cases

Author: pmk21

tests/ui/implicit_saturating_sub.rs

@@ -1,21 +1,85 @@
 #![warn(clippy::implicit_saturating_sub)]
 
 fn main() {
-    let mut end = 10;
-    let mut start = 5;
-    let mut i: u32 = end - start;
+    let end_8: u8 = 10;
+    let start_8: u8 = 5;
+    let mut i_8: u8 = end_8 - start_8;
 
-    if i > 0 {
-        i -= 1;
+    // Lint
+    if i_8 > 0 {
+        i_8 -= 1;
     }
 
-    match end {
+    match end_8 {
         10 => {
-            if i > 0 {
-                i -= 1;
+            // Lint
+            if i_8 > 0 {
+                i_8 -= 1;
             }
         },
-        11 => i += 1,
-        _ => i = 0,
+        11 => i_8 += 1,
+        _ => i_8 = 0,
     }
+
+    let end_16: u16 = 35;
+    let start_16: u16 = 40;
+
+    let mut i_16: u16 = end_16 - start_16;
+
+    // Lint
+    if i_16 > 0 {
+        i_16 -= 1;
+    }
+
+    let mut end_32: u32 = 7000;
+    let mut start_32: u32 = 7010;
+
+    let mut i_32: u32 = end_32 - start_32;
+
+    // Lint
+    if i_32 != 0 {
+        i_32 -= 1;
+    }
+
+    // No Lint
+    if i_32 > 0 {
+        i_16 += 1;
+    }
+
+    // No Lint
+    if i_32 != 0 {
+        end_32 -= 1;
+        start_32 += 1;
+    }
+
+    let mut end_64: u64 = 75001;
+    let mut start_64: u64 = 75000;
+
+    let mut i_64: u64 = end_64 - start_64;
+
+    // Lint
+    if i_64 > 0 {
+        i_64 -= 1;
+    }
+
+    // No Lint
+    if i_64 >= 1 {
+        i_64 -= 1;
+    }
+
+    // No Lint
+    if i_64 > 0 {
+        end_64 -= 1;
+    }
+
+    // Should signed integers trigger the lint ?
+    // let endi_64: i64 = 45;
+    // let starti_64: i64 = 44;
+
+    // let mut ii_64 = endi_64 - starti_64;
+
+    // Should this produce a warning
+    // if ii_64 > 0 {
+    //     ii_64 -= 1;
+    // }
 }

tests/ui/implicit_saturating_sub.stderr

@@ -1,20 +1,44 @@
 error: Implicitly performing saturating subtraction
-  --> $DIR/implicit_saturating_sub.rs:8:5
+  --> $DIR/implicit_saturating_sub.rs:9:5
    |
-LL | /     if i > 0 {
-LL | |         i -= 1;
+LL | /     if i_8 > 0 {
+LL | |         i_8 -= 1;
 LL | |     }
-   | |_____^ help: try: `i.saturating_sub(1);`
+   | |_____^ help: try: `i_8 = i_8.saturating_sub(1);`
    |
    = note: `-D clippy::implicit-saturating-sub` implied by `-D warnings`
 
 error: Implicitly performing saturating subtraction
-  --> $DIR/implicit_saturating_sub.rs:14:13
+  --> $DIR/implicit_saturating_sub.rs:16:13
    |
-LL | /             if i > 0 {
-LL | |                 i -= 1;
+LL | /             if i_8 > 0 {
+LL | |                 i_8 -= 1;
 LL | |             }
-   | |_____________^ help: try: `i.saturating_sub(1);`
+   | |_____________^ help: try: `i_8 = i_8.saturating_sub(1);`
 
-error: aborting due to 2 previous errors
+error: Implicitly performing saturating subtraction
+  --> $DIR/implicit_saturating_sub.rs:30:5
+   |
+LL | /     if i_16 > 0 {
+LL | |         i_16 -= 1;
+LL | |     }
+   | |_____^ help: try: `i_16 = i_16.saturating_sub(1);`
+
+error: Implicitly performing saturating subtraction
+  --> $DIR/implicit_saturating_sub.rs:40:5
+   |
+LL | /     if i_32 != 0 {
+LL | |         i_32 -= 1;
+LL | |     }
+   | |_____^ help: try: `i_32 = i_32.saturating_sub(1);`
+
+error: Implicitly performing saturating subtraction
+  --> $DIR/implicit_saturating_sub.rs:61:5
+   |
+LL | /     if i_64 > 0 {
+LL | |         i_64 -= 1;
+LL | |     }
+   | |_____^ help: try: `i_64 = i_64.saturating_sub(1);`
+
+error: aborting due to 5 previous errors