From 546be18e3a91e4844b0dacc76c9f055397b6d89e Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Sun, 13 Jun 2021 12:33:08 +0300
Subject: [PATCH] internal: check that coverage marks are always paired

---
 crates/hir_def/src/body/tests/block.rs | 10 +++---
 crates/ide_completion/src/render.rs    |  1 +
 xtask/src/tidy.rs                      | 49 +++++++++++++++++++++++++-
 3 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/crates/hir_def/src/body/tests/block.rs b/crates/hir_def/src/body/tests/block.rs
index bc3d0f13875..15c10d053f2 100644
--- a/crates/hir_def/src/body/tests/block.rs
+++ b/crates/hir_def/src/body/tests/block.rs
@@ -163,14 +163,14 @@ fn legacy_macro_items() {
     // correctly.
     check_at(
         r#"
-macro_rules! hit {
+macro_rules! mark {
     () => {
         struct Hit {}
     }
 }
 
 fn f() {
-    hit!();
+    mark!();
     $0
 }
 "#,
@@ -193,20 +193,20 @@ fn macro_resolve() {
 
 fn f() {
     fn nested() {
-        cov_mark::hit!(Hit);
+        cov_mark::mark!(Hit);
         $0
     }
 }
 //- /core.rs crate:core
 pub mod cov_mark {
     #[macro_export]
-    macro_rules! _hit {
+    macro_rules! _mark {
         ($name:ident) => {
             struct $name {}
         }
     }
 
-    pub use crate::_hit as hit;
+    pub use crate::_mark as mark;
 }
 "#,
         expect![[r#"
diff --git a/crates/ide_completion/src/render.rs b/crates/ide_completion/src/render.rs
index a5508163124..d8ca18c733e 100644
--- a/crates/ide_completion/src/render.rs
+++ b/crates/ide_completion/src/render.rs
@@ -1007,6 +1007,7 @@ fn go(…) []
 
     #[test]
     fn too_many_arguments() {
+        cov_mark::check!(too_many_arguments);
         check_relevance(
             r#"
 struct Foo;
diff --git a/xtask/src/tidy.rs b/xtask/src/tidy.rs
index 9447d463d0f..e6fa5868de5 100644
--- a/xtask/src/tidy.rs
+++ b/xtask/src/tidy.rs
@@ -1,4 +1,7 @@
-use std::path::{Path, PathBuf};
+use std::{
+    collections::HashSet,
+    path::{Path, PathBuf},
+};
 
 use xshell::{cmd, pushd, pushenv, read_file};
 
@@ -81,6 +84,7 @@ fn check_lsp_extensions_docs() {
 #[test]
 fn rust_files_are_tidy() {
     let mut tidy_docs = TidyDocs::default();
+    let mut tidy_marks = TidyMarks::default();
     for path in rust_files() {
         let text = read_file(&path).unwrap();
         check_todo(&path, &text);
@@ -88,8 +92,10 @@ fn rust_files_are_tidy() {
         check_trailing_ws(&path, &text);
         deny_clippy(&path, &text);
         tidy_docs.visit(&path, &text);
+        tidy_marks.visit(&path, &text);
     }
     tidy_docs.finish();
+    tidy_marks.finish();
 }
 
 #[test]
@@ -408,6 +414,39 @@ fn is_exclude_dir(p: &Path, dirs_to_exclude: &[&str]) -> bool {
         .any(|it| dirs_to_exclude.contains(&it))
 }
 
+#[derive(Default)]
+struct TidyMarks {
+    hits: HashSet<String>,
+    checks: HashSet<String>,
+}
+
+impl TidyMarks {
+    fn visit(&mut self, _path: &Path, text: &str) {
+        for line in text.lines() {
+            if let Some(mark) = find_mark(line, "hit") {
+                self.hits.insert(mark.to_string());
+            }
+            if let Some(mark) = find_mark(line, "check") {
+                self.checks.insert(mark.to_string());
+            }
+            if let Some(mark) = find_mark(line, "check_count") {
+                self.checks.insert(mark.to_string());
+            }
+        }
+    }
+
+    fn finish(self) {
+        assert!(!self.hits.is_empty());
+
+        let diff: Vec<_> =
+            self.hits.symmetric_difference(&self.checks).map(|it| it.as_str()).collect();
+
+        if !diff.is_empty() {
+            panic!("unpaired marks: {:?}", diff)
+        }
+    }
+}
+
 #[allow(deprecated)]
 fn stable_hash(text: &str) -> u64 {
     use std::hash::{Hash, Hasher, SipHasher};
@@ -417,3 +456,11 @@ fn stable_hash(text: &str) -> u64 {
     text.hash(&mut hasher);
     hasher.finish()
 }
+
+fn find_mark<'a>(text: &'a str, mark: &'static str) -> Option<&'a str> {
+    let idx = text.find(mark)?;
+    let text = text[idx + mark.len()..].strip_prefix("!(")?;
+    let idx = text.find(|c: char| !(c.is_alphanumeric() || c == '_'))?;
+    let text = &text[..idx];
+    Some(text)
+}