feat: implement manual_is_ascii_check lint

modify

fix: allow unused in test code

fix: types in doc comment

Update clippy_lints/src/manual_is_ascii_check.rs

Co-authored-by: Fridtjof Stoldt <xFrednet@gmail.com>

Update clippy_lints/src/manual_is_ascii_check.rs

Co-authored-by: Fridtjof Stoldt <xFrednet@gmail.com>

Update clippy_lints/src/manual_is_ascii_check.rs

Co-authored-by: Fridtjof Stoldt <xFrednet@gmail.com>

fix ui test result

fix: unnecessary format!

chore: apply feedbacks

* check msrvs also for const fn
* check applicability manually
* modify documents

3 files changed, 160 insertions, 0 deletions

diff --git a/tests/ui/manual_is_ascii_check.fixed b/tests/ui/manual_is_ascii_check.fixed
new file mode 100644
index 00000000000..765bb785994
--- /dev/null
+++ b/tests/ui/manual_is_ascii_check.fixed
@@ -0,0 +1,45 @@
+// run-rustfix
+
+#![feature(custom_inner_attributes)]
+#![allow(unused, dead_code)]
+#![warn(clippy::manual_is_ascii_check)]
+
+fn main() {
+    assert!('x'.is_ascii_lowercase());
+    assert!('X'.is_ascii_uppercase());
+    assert!(b'x'.is_ascii_lowercase());
+    assert!(b'X'.is_ascii_uppercase());
+
+    let num = '2';
+    assert!(num.is_ascii_digit());
+    assert!(b'1'.is_ascii_digit());
+    assert!('x'.is_ascii_alphabetic());
+
+    assert!(matches!('x', 'A'..='Z' | 'a'..='z' | '_'));
+}
+
+fn msrv_1_23() {
+    #![clippy::msrv = "1.23"]
+
+    assert!(matches!(b'1', b'0'..=b'9'));
+    assert!(matches!('X', 'A'..='Z'));
+    assert!(matches!('x', 'A'..='Z' | 'a'..='z'));
+}
+
+fn msrv_1_24() {
+    #![clippy::msrv = "1.24"]
+
+    assert!(b'1'.is_ascii_digit());
+    assert!('X'.is_ascii_uppercase());
+    assert!('x'.is_ascii_alphabetic());
+}
+
+fn msrv_1_46() {
+    #![clippy::msrv = "1.46"]
+    const FOO: bool = matches!('x', '0'..='9');
+}
+
+fn msrv_1_47() {
+    #![clippy::msrv = "1.47"]
+    const FOO: bool = 'x'.is_ascii_digit();
+}
diff --git a/tests/ui/manual_is_ascii_check.rs b/tests/ui/manual_is_ascii_check.rs
new file mode 100644
index 00000000000..be133161041
--- /dev/null
+++ b/tests/ui/manual_is_ascii_check.rs
@@ -0,0 +1,45 @@
+// run-rustfix
+
+#![feature(custom_inner_attributes)]
+#![allow(unused, dead_code)]
+#![warn(clippy::manual_is_ascii_check)]
+
+fn main() {
+    assert!(matches!('x', 'a'..='z'));
+    assert!(matches!('X', 'A'..='Z'));
+    assert!(matches!(b'x', b'a'..=b'z'));
+    assert!(matches!(b'X', b'A'..=b'Z'));
+
+    let num = '2';
+    assert!(matches!(num, '0'..='9'));
+    assert!(matches!(b'1', b'0'..=b'9'));
+    assert!(matches!('x', 'A'..='Z' | 'a'..='z'));
+
+    assert!(matches!('x', 'A'..='Z' | 'a'..='z' | '_'));
+}
+
+fn msrv_1_23() {
+    #![clippy::msrv = "1.23"]
+
+    assert!(matches!(b'1', b'0'..=b'9'));
+    assert!(matches!('X', 'A'..='Z'));
+    assert!(matches!('x', 'A'..='Z' | 'a'..='z'));
+}
+
+fn msrv_1_24() {
+    #![clippy::msrv = "1.24"]
+
+    assert!(matches!(b'1', b'0'..=b'9'));
+    assert!(matches!('X', 'A'..='Z'));
+    assert!(matches!('x', 'A'..='Z' | 'a'..='z'));
+}
+
+fn msrv_1_46() {
+    #![clippy::msrv = "1.46"]
+    const FOO: bool = matches!('x', '0'..='9');
+}
+
+fn msrv_1_47() {
+    #![clippy::msrv = "1.47"]
+    const FOO: bool = matches!('x', '0'..='9');
+}
diff --git a/tests/ui/manual_is_ascii_check.stderr b/tests/ui/manual_is_ascii_check.stderr
new file mode 100644
index 00000000000..c0a9d4db1a1
--- /dev/null
+++ b/tests/ui/manual_is_ascii_check.stderr
@@ -0,0 +1,70 @@
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:8:13
+   |
+LL |     assert!(matches!('x', 'a'..='z'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `'x'.is_ascii_lowercase()`
+   |
+   = note: `-D clippy::manual-is-ascii-check` implied by `-D warnings`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:9:13
+   |
+LL |     assert!(matches!('X', 'A'..='Z'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `'X'.is_ascii_uppercase()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:10:13
+   |
+LL |     assert!(matches!(b'x', b'a'..=b'z'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `b'x'.is_ascii_lowercase()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:11:13
+   |
+LL |     assert!(matches!(b'X', b'A'..=b'Z'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `b'X'.is_ascii_uppercase()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:14:13
+   |
+LL |     assert!(matches!(num, '0'..='9'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `num.is_ascii_digit()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:15:13
+   |
+LL |     assert!(matches!(b'1', b'0'..=b'9'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `b'1'.is_ascii_digit()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:16:13
+   |
+LL |     assert!(matches!('x', 'A'..='Z' | 'a'..='z'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `'x'.is_ascii_alphabetic()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:32:13
+   |
+LL |     assert!(matches!(b'1', b'0'..=b'9'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `b'1'.is_ascii_digit()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:33:13
+   |
+LL |     assert!(matches!('X', 'A'..='Z'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `'X'.is_ascii_uppercase()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:34:13
+   |
+LL |     assert!(matches!('x', 'A'..='Z' | 'a'..='z'));
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `'x'.is_ascii_alphabetic()`
+
+error: manual check for common ascii range
+  --> $DIR/manual_is_ascii_check.rs:44:23
+   |
+LL |     const FOO: bool = matches!('x', '0'..='9');
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `'x'.is_ascii_digit()`
+
+error: aborting due to 11 previous errors
+