Split indirect collects into their own test case

Author: JarredAllen

tests/ui/needless_collect.fixed

@@ -18,15 +18,4 @@ fn main() {
     sample.iter().collect::<HashSet<_>>().len();
     // Neither should this
     sample.iter().collect::<BTreeSet<_>>().len();
-    let indirect_positive = sample.iter().collect::<Vec<_>>();
-    indirect_positive
-        .into_iter()
-        .map(|x| (x, x + 1))
-        .collect::<HashMap<_, _>>();
-    let indirect_negative = sample.iter().collect::<Vec<_>>();
-    indirect_negative.len();
-    indirect_negative
-        .iter()
-        .map(|x| (*x, *x + 1))
-        .collect::<HashMap<_, _>>();
 }

tests/ui/needless_collect.rs

@@ -18,15 +18,4 @@ fn main() {
     sample.iter().collect::<HashSet<_>>().len();
     // Neither should this
     sample.iter().collect::<BTreeSet<_>>().len();
-    let indirect_positive = sample.iter().collect::<Vec<_>>();
-    indirect_positive
-        .into_iter()
-        .map(|x| (x, x + 1))
-        .collect::<HashMap<_, _>>();
-    let indirect_negative = sample.iter().collect::<Vec<_>>();
-    indirect_negative.len();
-    indirect_negative
-        .iter()
-        .map(|x| (*x, *x + 1))
-        .collect::<HashMap<_, _>>();
 }

tests/ui/needless_collect.stderr

@@ -1,21 +1,10 @@
-error: avoid using `collect()` when not needed
-  --> $DIR/needless_collect.rs:21:5
-   |
-LL |     let indirect_positive = sample.iter().collect::<Vec<_>>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: `-D clippy::needless-collect` implied by `-D warnings`
-help: Use the original Iterator instead of collecting it and then producing a new one
-   |
-LL |     
-LL |     sample.iter()
-   |
-
 error: avoid using `collect()` when not needed
   --> $DIR/needless_collect.rs:11:29
    |
 LL |     let len = sample.iter().collect::<Vec<_>>().len();
    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `count()`
+   |
+   = note: `-D clippy::needless-collect` implied by `-D warnings`
 
 error: avoid using `collect()` when not needed
   --> $DIR/needless_collect.rs:12:15
@@ -35,5 +24,5 @@ error: avoid using `collect()` when not needed
 LL |     sample.iter().map(|x| (x, x)).collect::<HashMap<_, _>>().len();
    |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `count()`
 
-error: aborting due to 5 previous errors
+error: aborting due to 4 previous errors
 

tests/ui/needless_collect_indirect.fixed

@@ -0,0 +1,26 @@
+// run-rustfix
+
+#[allow(unused)]
+
+use std::collections::{HashMap, VecDeque};
+
+fn main() {
+    let sample = [1; 5];
+    let indirect_iter = sample.iter().collect::<Vec<_>>();
+    indirect_iter
+        .into_iter()
+        .map(|x| (x, x + 1))
+        .collect::<HashMap<_, _>>();
+    let indirect_len = sample.iter().collect::<VecDeque<_>>();
+    indirect_len.len();
+    let indirect_empty = sample.iter().collect::<VecDeque<_>>();
+    indirect_empty.is_empty();
+    let indirect_contains = sample.iter().collect::<VecDeque<_>>();
+    indirect_contains.contains(&&5);
+    let indirect_negative = sample.iter().collect::<Vec<_>>();
+    indirect_negative.len();
+    indirect_negative
+        .into_iter()
+        .map(|x| (*x, *x + 1))
+        .collect::<HashMap<_, _>>();
+}

tests/ui/needless_collect_indirect.rs

@@ -0,0 +1,26 @@
+// run-rustfix
+
+#[allow(unused)]
+
+use std::collections::{HashMap, VecDeque};
+
+fn main() {
+    let sample = [1; 5];
+    let indirect_iter = sample.iter().collect::<Vec<_>>();
+    indirect_iter
+        .into_iter()
+        .map(|x| (x, x + 1))
+        .collect::<HashMap<_, _>>();
+    let indirect_len = sample.iter().collect::<VecDeque<_>>();
+    indirect_len.len();
+    let indirect_empty = sample.iter().collect::<VecDeque<_>>();
+    indirect_empty.is_empty();
+    let indirect_contains = sample.iter().collect::<VecDeque<_>>();
+    indirect_contains.contains(&&5);
+    let indirect_negative = sample.iter().collect::<Vec<_>>();
+    indirect_negative.len();
+    indirect_negative
+        .into_iter()
+        .map(|x| (*x, *x + 1))
+        .collect::<HashMap<_, _>>();
+}

tests/ui/needless_collect_indirect.stderr

@@ -0,0 +1,55 @@
+error: avoid using `collect()` when not needed
+  --> $DIR/needless_collect_indirect.rs:9:5
+   |
+LL | /     let indirect_iter = sample.iter().collect::<Vec<_>>();
+LL | |     indirect_iter
+   | |____^
+   |
+   = note: `-D clippy::needless-collect` implied by `-D warnings`
+help: Use the original Iterator instead of collecting it and then producing a new one
+   |
+LL |     
+LL |     sample.iter()
+   |
+
+error: avoid using `collect()` when not needed
+  --> $DIR/needless_collect_indirect.rs:14:5
+   |
+LL | /     let indirect_len = sample.iter().collect::<VecDeque<_>>();
+LL | |     indirect_len.len();
+   | |____^
+   |
+help: Take the original Iterator's count instead of collecting it and finding the length
+   |
+LL |     
+LL |     sample.iter().count();
+   |
+
+error: avoid using `collect()` when not needed
+  --> $DIR/needless_collect_indirect.rs:16:5
+   |
+LL | /     let indirect_empty = sample.iter().collect::<VecDeque<_>>();
+LL | |     indirect_empty.is_empty();
+   | |____^
+   |
+help: Check if the original Iterator has anything instead of collecting it and seeing if it's empty
+   |
+LL |     
+LL |     sample.iter().next().is_none();
+   |
+
+error: avoid using `collect()` when not needed
+  --> $DIR/needless_collect_indirect.rs:18:5
+   |
+LL | /     let indirect_contains = sample.iter().collect::<VecDeque<_>>();
+LL | |     indirect_contains.contains(&&5);
+   | |____^
+   |
+help: Check if the original Iterator contains an element instead of collecting then checking
+   |
+LL |     
+LL |     sample.iter().any(|x| x == &&5);
+   |
+
+error: aborting due to 4 previous errors
+