Add `BTreeSet` to set_contains_or_insert

* Detect `BTreeSet::contains` + `BTreeSet::insert` usage in the same way as with the `HashSet`.

2 files changed, 140 insertions, 15 deletions

diff --git a/tests/ui/set_contains_or_insert.rs b/tests/ui/set_contains_or_insert.rs
index 8465007402a..d3a3e1c878b 100644
--- a/tests/ui/set_contains_or_insert.rs
+++ b/tests/ui/set_contains_or_insert.rs
@@ -3,17 +3,78 @@
 #![allow(clippy::needless_borrow)]
 #![warn(clippy::set_contains_or_insert)]
 
-use std::collections::HashSet;
+use std::collections::{BTreeSet, HashSet};
 
-fn main() {
-    should_warn_cases();
+fn should_warn_hashset() {
+    let mut set = HashSet::new();
+    let value = 5;
+
+    if !set.contains(&value) {
+        set.insert(value);
+        println!("Just a comment");
+    }
+
+    if set.contains(&value) {
+        set.insert(value);
+        println!("Just a comment");
+    }
+
+    if !set.contains(&value) {
+        set.insert(value);
+    }
 
-    should_not_warn_cases();
+    if !!set.contains(&value) {
+        set.insert(value);
+        println!("Just a comment");
+    }
+
+    if (&set).contains(&value) {
+        set.insert(value);
+    }
+
+    let borrow_value = &6;
+    if !set.contains(borrow_value) {
+        set.insert(*borrow_value);
+    }
+
+    let borrow_set = &mut set;
+    if !borrow_set.contains(&value) {
+        borrow_set.insert(value);
+    }
 }
 
-fn should_warn_cases() {
+fn should_not_warn_hashset() {
     let mut set = HashSet::new();
     let value = 5;
+    let another_value = 6;
+
+    if !set.contains(&value) {
+        set.insert(another_value);
+    }
+
+    if !set.contains(&value) {
+        println!("Just a comment");
+    }
+
+    if simply_true() {
+        set.insert(value);
+    }
+
+    if !set.contains(&value) {
+        set.replace(value); //it is not insert
+        println!("Just a comment");
+    }
+
+    if set.contains(&value) {
+        println!("value is already in set");
+    } else {
+        set.insert(value);
+    }
+}
+
+fn should_warn_btreeset() {
+    let mut set = BTreeSet::new();
+    let value = 5;
 
     if !set.contains(&value) {
         set.insert(value);
@@ -49,8 +110,8 @@ fn should_warn_cases() {
     }
 }
 
-fn should_not_warn_cases() {
-    let mut set = HashSet::new();
+fn should_not_warn_btreeset() {
+    let mut set = BTreeSet::new();
     let value = 5;
     let another_value = 6;
 
@@ -81,3 +142,11 @@ fn should_not_warn_cases() {
 fn simply_true() -> bool {
     true
 }
+
+// This is placed last in order to be able to add new tests without changing line numbers
+fn main() {
+    should_warn_hashset();
+    should_warn_btreeset();
+    should_not_warn_hashset();
+    should_not_warn_btreeset();
+}
diff --git a/tests/ui/set_contains_or_insert.stderr b/tests/ui/set_contains_or_insert.stderr
index 507e20964fc..14ad6300544 100644
--- a/tests/ui/set_contains_or_insert.stderr
+++ b/tests/ui/set_contains_or_insert.stderr
@@ -1,5 +1,5 @@
 error: usage of `HashSet::insert` after `HashSet::contains`
-  --> tests/ui/set_contains_or_insert.rs:18:13
+  --> tests/ui/set_contains_or_insert.rs:12:13
    |
 LL |     if !set.contains(&value) {
    |             ^^^^^^^^^^^^^^^^
@@ -10,7 +10,7 @@ LL |         set.insert(value);
    = help: to override `-D warnings` add `#[allow(clippy::set_contains_or_insert)]`
 
 error: usage of `HashSet::insert` after `HashSet::contains`
-  --> tests/ui/set_contains_or_insert.rs:23:12
+  --> tests/ui/set_contains_or_insert.rs:17:12
    |
 LL |     if set.contains(&value) {
    |            ^^^^^^^^^^^^^^^^
@@ -18,7 +18,7 @@ LL |         set.insert(value);
    |             ^^^^^^^^^^^^^
 
 error: usage of `HashSet::insert` after `HashSet::contains`
-  --> tests/ui/set_contains_or_insert.rs:28:13
+  --> tests/ui/set_contains_or_insert.rs:22:13
    |
 LL |     if !set.contains(&value) {
    |             ^^^^^^^^^^^^^^^^
@@ -26,7 +26,7 @@ LL |         set.insert(value);
    |             ^^^^^^^^^^^^^
 
 error: usage of `HashSet::insert` after `HashSet::contains`
-  --> tests/ui/set_contains_or_insert.rs:32:14
+  --> tests/ui/set_contains_or_insert.rs:26:14
    |
 LL |     if !!set.contains(&value) {
    |              ^^^^^^^^^^^^^^^^
@@ -34,7 +34,7 @@ LL |         set.insert(value);
    |             ^^^^^^^^^^^^^
 
 error: usage of `HashSet::insert` after `HashSet::contains`
-  --> tests/ui/set_contains_or_insert.rs:37:15
+  --> tests/ui/set_contains_or_insert.rs:31:15
    |
 LL |     if (&set).contains(&value) {
    |               ^^^^^^^^^^^^^^^^
@@ -42,7 +42,7 @@ LL |         set.insert(value);
    |             ^^^^^^^^^^^^^
 
 error: usage of `HashSet::insert` after `HashSet::contains`
-  --> tests/ui/set_contains_or_insert.rs:42:13
+  --> tests/ui/set_contains_or_insert.rs:36:13
    |
 LL |     if !set.contains(borrow_value) {
    |             ^^^^^^^^^^^^^^^^^^^^^^
@@ -50,12 +50,68 @@ LL |         set.insert(*borrow_value);
    |             ^^^^^^^^^^^^^^^^^^^^^
 
 error: usage of `HashSet::insert` after `HashSet::contains`
-  --> tests/ui/set_contains_or_insert.rs:47:20
+  --> tests/ui/set_contains_or_insert.rs:41:20
    |
 LL |     if !borrow_set.contains(&value) {
    |                    ^^^^^^^^^^^^^^^^
 LL |         borrow_set.insert(value);
    |                    ^^^^^^^^^^^^^
 
-error: aborting due to 7 previous errors
+error: usage of `BTreeSet::insert` after `BTreeSet::contains`
+  --> tests/ui/set_contains_or_insert.rs:79:13
+   |
+LL |     if !set.contains(&value) {
+   |             ^^^^^^^^^^^^^^^^
+LL |         set.insert(value);
+   |             ^^^^^^^^^^^^^
+
+error: usage of `BTreeSet::insert` after `BTreeSet::contains`
+  --> tests/ui/set_contains_or_insert.rs:84:12
+   |
+LL |     if set.contains(&value) {
+   |            ^^^^^^^^^^^^^^^^
+LL |         set.insert(value);
+   |             ^^^^^^^^^^^^^
+
+error: usage of `BTreeSet::insert` after `BTreeSet::contains`
+  --> tests/ui/set_contains_or_insert.rs:89:13
+   |
+LL |     if !set.contains(&value) {
+   |             ^^^^^^^^^^^^^^^^
+LL |         set.insert(value);
+   |             ^^^^^^^^^^^^^
+
+error: usage of `BTreeSet::insert` after `BTreeSet::contains`
+  --> tests/ui/set_contains_or_insert.rs:93:14
+   |
+LL |     if !!set.contains(&value) {
+   |              ^^^^^^^^^^^^^^^^
+LL |         set.insert(value);
+   |             ^^^^^^^^^^^^^
+
+error: usage of `BTreeSet::insert` after `BTreeSet::contains`
+  --> tests/ui/set_contains_or_insert.rs:98:15
+   |
+LL |     if (&set).contains(&value) {
+   |               ^^^^^^^^^^^^^^^^
+LL |         set.insert(value);
+   |             ^^^^^^^^^^^^^
+
+error: usage of `BTreeSet::insert` after `BTreeSet::contains`
+  --> tests/ui/set_contains_or_insert.rs:103:13
+   |
+LL |     if !set.contains(borrow_value) {
+   |             ^^^^^^^^^^^^^^^^^^^^^^
+LL |         set.insert(*borrow_value);
+   |             ^^^^^^^^^^^^^^^^^^^^^
+
+error: usage of `BTreeSet::insert` after `BTreeSet::contains`
+  --> tests/ui/set_contains_or_insert.rs:108:20
+   |
+LL |     if !borrow_set.contains(&value) {
+   |                    ^^^^^^^^^^^^^^^^
+LL |         borrow_set.insert(value);
+   |                    ^^^^^^^^^^^^^
+
+error: aborting due to 14 previous errors