Add fixed_path_existence test

Cargo.toml

@@ -46,11 +46,13 @@ if_chain = "1.0"
 itertools = "0.10.1"
 quote = "1.0"
 serde = { version = "1.0.125", features = ["derive"] }
+serde_json = "1.0"
 syn = { version = "1.0", features = ["full"] }
 futures = "0.3"
 parking_lot = "0.11.2"
 tokio = { version = "1", features = ["io-util"] }
 rustc-semver = "1.1"
+walkdir = "2.3"
 
 [build-dependencies]
 rustc_tools_util = { version = "0.2", path = "rustc_tools_util" }

clippy_lints/src/lib.rs

@@ -501,6 +501,9 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     {
         if std::env::var("ENABLE_METADATA_COLLECTION").eq(&Ok("1".to_string())) {
             store.register_late_pass(|| Box::new(utils::internal_lints::metadata_collector::MetadataCollector::new()));
+        }
+
+        if std::env::var("DISABLE_STANDARD_LINTS").eq(&Ok("1".to_string())) {
             return;
         }
     }

tests/dogfood.rs

@@ -25,43 +25,206 @@ fn dogfood_clippy() {
     }
 }
 
-#[test]
-#[ignore]
-#[cfg(feature = "internal")]
-fn run_metadata_collection_lint() {
-    use std::fs::File;
-    use std::time::SystemTime;
-
-    // Setup for validation
-    let metadata_output_path = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("util/gh-pages/lints.json");
-    let start_time = SystemTime::now();
-
-    // Run collection as is
-    std::env::set_var("ENABLE_METADATA_COLLECTION", "1");
-    run_clippy_for_package("clippy_lints", &["-A", "unfulfilled_lint_expectations"]);
-
-    // Check if cargo caching got in the way
-    if let Ok(file) = File::open(metadata_output_path) {
-        if let Ok(metadata) = file.metadata() {
-            if let Ok(last_modification) = metadata.modified() {
-                if last_modification > start_time {
-                    // The output file has been modified. Most likely by a hungry
-                    // metadata collection monster. So We'll return.
-                    return;
+#[cfg(all(test, feature = "internal"))]
+mod internal {
+    use super::run_clippy_for_package;
+    use if_chain::if_chain;
+    use serde::Deserialize;
+    use std::collections::HashMap;
+    use std::ffi::OsStr;
+    use std::fs::{read_to_string, File};
+    use std::io::BufReader;
+    use std::path::PathBuf;
+    use walkdir::WalkDir;
+
+    static UI_TEST_PATH: std::lazy::SyncLazy<PathBuf> =
+        std::lazy::SyncLazy::new(|| PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("tests/ui"));
+
+    static METADATA_OUTPUT_PATH: std::lazy::SyncLazy<PathBuf> =
+        std::lazy::SyncLazy::new(|| PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("util/gh-pages/lints.json"));
+
+    #[derive(Debug, Deserialize)]
+    pub struct LintMetadata {
+        id: String,
+        applicability: Option<ApplicabilityInfo>,
+    }
+
+    #[derive(Debug, Deserialize)]
+    struct ApplicabilityInfo {
+        applicability: Option<String>,
+    }
+
+    const MACHINE_APPLICABLE: &str = "MachineApplicable";
+
+    const KNOWN_EXCEPTIONS: [&str; 33] = [
+        "assign_ops2.stderr",
+        "cast_size_32bit.stderr",
+        "char_lit_as_u8.stderr",
+        "cmp_owned/without_suggestion.stderr",
+        "dbg_macro.stderr",
+        "deref_addrof_double_trigger.stderr",
+        "doc/unbalanced_ticks.stderr",
+        "eprint_with_newline.stderr",
+        "explicit_counter_loop.stderr",
+        "iter_skip_next_unfixable.stderr",
+        "let_and_return.stderr",
+        "literals.stderr",
+        "map_flatten.stderr",
+        "map_unwrap_or.stderr",
+        "match_bool.stderr",
+        "mem_replace_macro.stderr",
+        "needless_arbitrary_self_type_unfixable.stderr",
+        "needless_borrow_pat.stderr",
+        "needless_for_each_unfixable.stderr",
+        "nonminimal_bool.stderr",
+        "print_literal.stderr",
+        "print_with_newline.stderr",
+        "redundant_static_lifetimes_multiple.stderr",
+        "result_map_unit_fn_unfixable.stderr",
+        "search_is_some.stderr",
+        "string_add.stderr",
+        "toplevel_ref_arg_non_rustfix.stderr",
+        "unit_arg.stderr",
+        "unnecessary_clone.stderr",
+        "unnecessary_lazy_eval_unfixable.stderr",
+        "write_literal_2.stderr",
+        "write_literal.stderr",
+        "write_with_newline.stderr",
+    ];
+
+    #[test]
+    fn known_exceptions_accuracy() {
+        for filename in KNOWN_EXCEPTIONS {
+            let stderr_path = UI_TEST_PATH.join(filename);
+            assert!(
+                stderr_path.exists(),
+                "`{}` does not exists",
+                stderr_path.strip_prefix(env!("CARGO_MANIFEST_DIR")).unwrap().display()
+            );
+            let fixed_path = stderr_path.with_extension("fixed");
+            assert!(
+                !fixed_path.exists(),
+                "`{}` exists",
+                fixed_path.strip_prefix(env!("CARGO_MANIFEST_DIR")).unwrap().display()
+            );
+        }
+    }
+
+    #[test]
+    fn fixed_path_existence() {
+        collect_metadata(false);
+
+        let lints = read_metadata();
+
+        let mut lint_map = HashMap::new();
+        for lint in lints {
+            lint_map.insert(lint.id, lint.applicability.and_then(|app| app.applicability));
+        }
+
+        for entry in WalkDir::new(&*UI_TEST_PATH) {
+            let entry = entry.unwrap();
+
+            if KNOWN_EXCEPTIONS.contains(&&*entry.path().strip_prefix(&*UI_TEST_PATH).unwrap().to_string_lossy()) {
+                continue;
+            }
+
+            if entry.path().extension() != Some(OsStr::new("stderr")) {
+                continue;
+            };
+
+            let stderr_path = entry.path();
+
+            let stderr_contents = read_to_string(stderr_path).unwrap();
+
+            let lint_ids = stderr_contents.lines().filter_map(|line| {
+                const PREFIX: &str = "`-D clippy::";
+                const SUFFIX: &str = "`";
+                if_chain! {
+                    if let Some(start) = line.find(PREFIX).map(|n| n + PREFIX.len());
+                    if let Some(end) = line[start..].find(SUFFIX);
+                    then {
+                        Some(line[start..][..end].replace('-', "_"))
+                    } else {
+                        None
+                    }
                 }
+            });
+
+            let mach_app_lint_ids = lint_ids
+                .filter(|id| {
+                    lint_map
+                        .get(id)
+                        .unwrap()
+                        .as_ref()
+                        .map_or(false, |s| s == MACHINE_APPLICABLE)
+                })
+                .collect::<Vec<_>>();
+
+            if !mach_app_lint_ids.is_empty() {
+                let fixed_path = stderr_path.with_extension("fixed");
+                assert!(
+                    fixed_path.exists(),
+                    "`{}` does not exist though `{}` mentions the following `{}` lints: {:#?}",
+                    fixed_path.strip_prefix(env!("CARGO_MANIFEST_DIR")).unwrap().display(),
+                    stderr_path.strip_prefix(env!("CARGO_MANIFEST_DIR")).unwrap().display(),
+                    MACHINE_APPLICABLE,
+                    mach_app_lint_ids
+                );
             }
         }
     }
 
-    // Force cargo to invalidate the caches
-    filetime::set_file_mtime(
-        PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("clippy_lints/src/lib.rs"),
-        filetime::FileTime::now(),
-    )
-    .unwrap();
+    #[test]
+    #[ignore]
+    fn run_metadata_collection_lint() {
+        collect_metadata(true);
+    }
+
+    fn collect_metadata(disable_standard_lints: bool) {
+        use std::time::SystemTime;
+
+        // Setup for validation
+        let start_time = SystemTime::now();
 
-    // Running the collection again
-    run_clippy_for_package("clippy_lints", &["-A", "unfulfilled_lint_expectations"]);
+        // Run collection as is
+        std::env::set_var("ENABLE_METADATA_COLLECTION", "1");
+        let args: &[&str] = if disable_standard_lints {
+            std::env::set_var("DISABLE_STANDARD_LINTS", "1");
+            &["-A", "unfulfilled_lint_expectations"]
+        } else {
+            &[]
+        };
+        run_clippy_for_package("clippy_lints", args);
+
+        // Check if cargo caching got in the way
+        if let Ok(file) = File::open(&*METADATA_OUTPUT_PATH) {
+            if let Ok(metadata) = file.metadata() {
+                if let Ok(last_modification) = metadata.modified() {
+                    if last_modification > start_time {
+                        // The output file has been modified. Most likely by a hungry
+                        // metadata collection monster. So We'll return.
+                        return;
+                    }
+                }
+            }
+        }
+
+        // Force cargo to invalidate the caches
+        filetime::set_file_mtime(
+            PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("clippy_lints/src/lib.rs"),
+            filetime::FileTime::now(),
+        )
+        .unwrap();
+
+        // Running the collection again
+        run_clippy_for_package("clippy_lints", args);
+    }
+
+    fn read_metadata() -> Vec<LintMetadata> {
+        let file = File::open(&*METADATA_OUTPUT_PATH).unwrap();
+        let reader = BufReader::new(file);
+        serde_json::from_reader(reader).unwrap()
+    }
 }
 
 fn run_clippy_for_package(project: &str, args: &[&str]) {

tests/ui/crashes/ice-8250.fixed

@@ -0,0 +1,7 @@
+// run-rustfix
+fn _f(s: &str) -> Option<()> {
+    let _ = s[1..].split('.').next()?;
+    Some(())
+}
+
+fn main() {}

tests/ui/crashes/ice-8250.rs

@@ -1,3 +1,4 @@
+// run-rustfix
 fn _f(s: &str) -> Option<()> {
     let _ = s[1..].splitn(2, '.').next()?;
     Some(())

tests/ui/crashes/ice-8250.stderr

@@ -1,5 +1,5 @@
 error: unnecessary use of `splitn`
-  --> $DIR/ice-8250.rs:2:13
+  --> $DIR/ice-8250.rs:3:13
    |
 LL |     let _ = s[1..].splitn(2, '.').next()?;
    |             ^^^^^^^^^^^^^^^^^^^^^ help: try this: `s[1..].split('.')`

tests/ui/crashes/ice-8821.fixed

@@ -0,0 +1,9 @@
+// run-rustfix
+#![warn(clippy::let_unit_value)]
+
+fn f() {}
+static FN: fn() = f;
+
+fn main() {
+    FN();
+}

tests/ui/crashes/ice-8821.rs

@@ -1,3 +1,4 @@
+// run-rustfix
 #![warn(clippy::let_unit_value)]
 
 fn f() {}

tests/ui/crashes/ice-8821.stderr

@@ -1,5 +1,5 @@
 error: this let-binding has unit value
-  --> $DIR/ice-8821.rs:7:5
+  --> $DIR/ice-8821.rs:8:5
    |
 LL |     let _: () = FN();
    |     ^^^^^^^^^^^^^^^^^ help: omit the `let` binding: `FN();`