Rollup merge of #73839 - crlf0710:snapshot_the_reality, r=Manishearth

Split and expand nonstandard-style lints unicode unit test.

RFC 2457 requested that the `nonstandard_style` series of linted be adjusted to cover the non_ascii_identifier case. However when i read the code of those implementations, it seems they're already supporting non_ascii_identifiers. But the exact rules is a little different than what's proposed in RFC 2457.

So I splitted and expanded the existing test case to try to exercise every branch in the code. I think it'll also be easier to examine the cases in these unit tests to see whether it's ok to just leave them as is, or some adjustments are needed.

r? @Manishearth

src/test/ui/lint/lint-nonstandard-style-unicode-1.rs

@@ -0,0 +1,50 @@
+#![allow(dead_code)]
+
+#![forbid(non_camel_case_types)]
+#![feature(non_ascii_idents)]
+
+// Some scripts (e.g., hiragana) don't have a concept of
+// upper/lowercase
+
+// 1. non_camel_case_types
+
+// Can start with non-lowercase letter
+struct Θχ;
+struct ヒa;
+
+struct χa;
+//~^ ERROR type `χa` should have an upper camel case name
+
+// If there's already leading or trailing underscores, they get trimmed before checking.
+// This is fine:
+struct _ヒb;
+
+// This is not:
+struct __χa;
+//~^ ERROR type `__χa` should have an upper camel case name
+
+// Besides this, we cannot have two continous underscores in the middle.
+
+struct 对__否;
+//~^ ERROR type `对__否` should have an upper camel case name
+
+struct ヒ__χ;
+//~^ ERROR type `ヒ__χ` should have an upper camel case name
+
+// also cannot have lowercase letter next to a underscore.
+// so this triggers the lint:
+
+struct Hello_你好;
+//~^ ERROR type `Hello_你好` should have an upper camel case name
+
+struct Hello_World;
+//~^ ERROR type `Hello_World` should have an upper camel case name
+
+struct 你_ӟ;
+//~^ ERROR type `你_ӟ` should have an upper camel case name
+
+// and this is ok:
+
+struct 你_好;
+
+fn main() {}

src/test/ui/lint/lint-nonstandard-style-unicode-1.stderr

@@ -0,0 +1,50 @@
+error: type `χa` should have an upper camel case name
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:15:8
+   |
+LL | struct χa;
+   |        ^^ help: convert the identifier to upper camel case: `Χa`
+   |
+note: the lint level is defined here
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:3:11
+   |
+LL | #![forbid(non_camel_case_types)]
+   |           ^^^^^^^^^^^^^^^^^^^^
+
+error: type `__χa` should have an upper camel case name
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:23:8
+   |
+LL | struct __χa;
+   |        ^^^^ help: convert the identifier to upper camel case: `Χa`
+
+error: type `对__否` should have an upper camel case name
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:28:8
+   |
+LL | struct 对__否;
+   |        ^^^^^^ help: convert the identifier to upper camel case: `对_否`
+
+error: type `ヒ__χ` should have an upper camel case name
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:31:8
+   |
+LL | struct ヒ__χ;
+   |        ^^^^^ help: convert the identifier to upper camel case: `ヒΧ`
+
+error: type `Hello_你好` should have an upper camel case name
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:37:8
+   |
+LL | struct Hello_你好;
+   |        ^^^^^^^^^^ help: convert the identifier to upper camel case: `Hello你好`
+
+error: type `Hello_World` should have an upper camel case name
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:40:8
+   |
+LL | struct Hello_World;
+   |        ^^^^^^^^^^^ help: convert the identifier to upper camel case: `HelloWorld`
+
+error: type `你_ӟ` should have an upper camel case name
+  --> $DIR/lint-nonstandard-style-unicode-1.rs:43:8
+   |
+LL | struct 你_ӟ;
+   |        ^^^^ help: convert the identifier to upper camel case: `你Ӟ`
+
+error: aborting due to 7 previous errors
+

src/test/ui/lint/lint-nonstandard-style-unicode-2.rs

@@ -0,0 +1,30 @@
+#![allow(dead_code)]
+
+#![forbid(non_snake_case)]
+#![feature(non_ascii_idents)]
+
+// Some scripts (e.g., hiragana) don't have a concept of
+// upper/lowercase
+
+// 2. non_snake_case
+
+// Can only use non-uppercase letters.
+// So this works:
+
+fn 编程() {}
+
+// but this doesn't:
+
+fn Ц() {}
+//~^ ERROR function `Ц` should have a snake case name
+
+// besides this, you cannot use continous underscores in the middle
+
+fn 分__隔() {}
+//~^ ERROR function `分__隔` should have a snake case name
+
+// but you can use them both at the beginning and at the end.
+
+fn _______不_连_续_的_存_在_______() {}
+
+fn main() {}

src/test/ui/lint/lint-nonstandard-style-unicode-2.stderr

@@ -0,0 +1,20 @@
+error: function `Ц` should have a snake case name
+  --> $DIR/lint-nonstandard-style-unicode-2.rs:18:4
+   |
+LL | fn Ц() {}
+   |    ^ help: convert the identifier to snake case: `ц`
+   |
+note: the lint level is defined here
+  --> $DIR/lint-nonstandard-style-unicode-2.rs:3:11
+   |
+LL | #![forbid(non_snake_case)]
+   |           ^^^^^^^^^^^^^^
+
+error: function `分__隔` should have a snake case name
+  --> $DIR/lint-nonstandard-style-unicode-2.rs:23:4
+   |
+LL | fn 分__隔() {}
+   |    ^^^^^^ help: convert the identifier to snake case: `分_隔`
+
+error: aborting due to 2 previous errors
+

src/test/ui/lint/lint-nonstandard-style-unicode-3.rs

@@ -0,0 +1,25 @@
+#![allow(dead_code)]
+
+#![forbid(non_upper_case_globals)]
+#![feature(non_ascii_idents)]
+
+// Some scripts (e.g., hiragana) don't have a concept of
+// upper/lowercase
+
+// 3. non_upper_case_globals
+
+// Can only use non-lowercase letters.
+// So this works:
+
+static ラ: usize = 0;
+
+// but this doesn't:
+
+static τεχ: f32 = 3.14159265;
+//~^ ERROR static variable `τεχ` should have an upper case name
+
+// This has no limit at all on underscore usages.
+
+static __密__封__线__内__禁__止__答__题__: bool = true;
+
+fn main() {}

src/test/ui/lint/lint-nonstandard-style-unicode-3.stderr

@@ -0,0 +1,14 @@
+error: static variable `τεχ` should have an upper case name
+  --> $DIR/lint-nonstandard-style-unicode-3.rs:18:8
+   |
+LL | static τεχ: f32 = 3.14159265;
+   |        ^^^ help: convert the identifier to upper case: `ΤΕΧ`
+   |
+note: the lint level is defined here
+  --> $DIR/lint-nonstandard-style-unicode-3.rs:3:11
+   |
+LL | #![forbid(non_upper_case_globals)]
+   |           ^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+