4 files changed, 53 insertions, 18 deletions

diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 4dbabdba7..078c83f75 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -859,12 +859,12 @@ fn manual(fields: &[(&'static str, &'static str, &[&str], &str)]) -> String {
 mod tests {
     use std::fs;
 
-    use test_utils::project_dir;
+    use test_utils::{ensure_file_contents, project_root};
 
     use super::*;
 
     #[test]
-    fn schema_in_sync_with_package_json() {
+    fn generate_package_json_config() {
         let s = Config::json_schema();
         let schema = format!("{:#}", s);
         let mut schema = schema
@@ -877,7 +877,7 @@ mod tests {
             .to_string();
         schema.push_str(",\n");
 
-        let package_json_path = project_dir().join("editors/code/package.json");
+        let package_json_path = project_root().join("editors/code/package.json");
         let mut package_json = fs::read_to_string(&package_json_path).unwrap();
 
         let start_marker = "                \"$generated-start\": false,\n";
@@ -885,19 +885,18 @@ mod tests {
 
         let start = package_json.find(start_marker).unwrap() + start_marker.len();
         let end = package_json.find(end_marker).unwrap();
+
         let p = remove_ws(&package_json[start..end]);
         let s = remove_ws(&schema);
-
         if !p.contains(&s) {
             package_json.replace_range(start..end, &schema);
-            fs::write(&package_json_path, &mut package_json).unwrap();
-            panic!("new config, updating package.json")
+            ensure_file_contents(&package_json_path, &package_json)
         }
     }
 
     #[test]
-    fn schema_in_sync_with_docs() {
-        let docs_path = project_dir().join("docs/user/generated_config.adoc");
+    fn generate_config_documentation() {
+        let docs_path = project_root().join("docs/user/generated_config.adoc");
         let current = fs::read_to_string(&docs_path).unwrap();
         let expected = ConfigData::manual();
 
diff --git a/crates/syntax/src/tests.rs b/crates/syntax/src/tests.rs
index b2c06e24f..ba0ccfaed 100644
--- a/crates/syntax/src/tests.rs
+++ b/crates/syntax/src/tests.rs
@@ -7,7 +7,7 @@ use std::{
 use ast::NameOwner;
 use expect_test::expect_file;
 use rayon::prelude::*;
-use test_utils::{bench, bench_fixture, project_dir, skip_slow_tests};
+use test_utils::{bench, bench_fixture, project_root, skip_slow_tests};
 
 use crate::{ast, fuzz, tokenize, AstNode, SourceFile, SyntaxError, TextRange, TextSize, Token};
 
@@ -153,7 +153,7 @@ fn reparse_fuzz_tests() {
 /// Test that Rust-analyzer can parse and validate the rust-analyzer
 #[test]
 fn self_hosting_parsing() {
-    let dir = project_dir().join("crates");
+    let dir = project_root().join("crates");
     let files = walkdir::WalkDir::new(dir)
         .into_iter()
         .filter_entry(|entry| {
@@ -193,7 +193,7 @@ fn self_hosting_parsing() {
 }
 
 fn test_data_dir() -> PathBuf {
-    project_dir().join("crates/syntax/test_data")
+    project_root().join("crates/syntax/test_data")
 }
 
 fn assert_errors_are_present(errors: &[SyntaxError], path: &Path) {
diff --git a/crates/test_utils/src/bench_fixture.rs b/crates/test_utils/src/bench_fixture.rs
index d775e2cc9..3a37c4473 100644
--- a/crates/test_utils/src/bench_fixture.rs
+++ b/crates/test_utils/src/bench_fixture.rs
@@ -4,7 +4,7 @@ use std::fs;
 
 use stdx::format_to;
 
-use crate::project_dir;
+use crate::project_root;
 
 pub fn big_struct() -> String {
     let n = 1_000;
@@ -32,11 +32,11 @@ struct S{} {{
 }
 
 pub fn glorious_old_parser() -> String {
-    let path = project_dir().join("bench_data/glorious_old_parser");
+    let path = project_root().join("bench_data/glorious_old_parser");
     fs::read_to_string(&path).unwrap()
 }
 
 pub fn numerous_macro_rules() -> String {
-    let path = project_dir().join("bench_data/numerous_macro_rules");
+    let path = project_root().join("bench_data/numerous_macro_rules");
     fs::read_to_string(&path).unwrap()
 }
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 27b05e34b..6041ab5e4 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -14,11 +14,11 @@ mod fixture;
 use std::{
     convert::{TryFrom, TryInto},
     env, fs,
-    path::PathBuf,
+    path::{Path, PathBuf},
 };
 
 use profile::StopWatch;
-use stdx::lines_with_ends;
+use stdx::{is_ci, lines_with_ends};
 use text_size::{TextRange, TextSize};
 
 pub use dissimilar::diff as __diff;
@@ -288,14 +288,14 @@ pub fn skip_slow_tests() -> bool {
     if should_skip {
         eprintln!("ignoring slow test")
     } else {
-        let path = project_dir().join("./target/.slow_tests_cookie");
+        let path = project_root().join("./target/.slow_tests_cookie");
         fs::write(&path, ".").unwrap();
     }
     should_skip
 }
 
 /// Returns the path to the root directory of `rust-analyzer` project.
-pub fn project_dir() -> PathBuf {
+pub fn project_root() -> PathBuf {
     let dir = env!("CARGO_MANIFEST_DIR");
     PathBuf::from(dir).parent().unwrap().parent().unwrap().to_owned()
 }
@@ -353,3 +353,39 @@ pub fn bench(label: &'static str) -> impl Drop {
 
     Bencher { sw: StopWatch::start(), label }
 }
+
+/// Checks that the `file` has the specified `contents`. If that is not the
+/// case, updates the file and then fails the test.
+pub fn ensure_file_contents(file: &Path, contents: &str) {
+    if let Err(()) = try_ensure_file_contents(file, contents) {
+        panic!("Some files were not up-to-date");
+    }
+}
+
+/// Checks that the `file` has the specified `contents`. If that is not the
+/// case, updates the file and return an Error.
+pub fn try_ensure_file_contents(file: &Path, contents: &str) -> Result<(), ()> {
+    match std::fs::read_to_string(file) {
+        Ok(old_contents) if normalize_newlines(&old_contents) == normalize_newlines(contents) => {
+            return Ok(())
+        }
+        _ => (),
+    }
+    let display_path = file.strip_prefix(&project_root()).unwrap_or(file);
+    eprintln!(
+        "\n\x1b[31;1merror\x1b[0m: {} was not up-to-date, updating\n",
+        display_path.display()
+    );
+    if is_ci() {
+        eprintln!("    NOTE: run `cargo test` locally and commit the updated files\n");
+    }
+    if let Some(parent) = file.parent() {
+        let _ = std::fs::create_dir_all(parent);
+    }
+    std::fs::write(file, contents).unwrap();
+    Err(())
+}
+
+fn normalize_newlines(s: &str) -> String {
+    s.replace("\r\n", "\n")
+}