Remove unused collect_metadata function

tests/dogfood.rs

@@ -6,11 +6,9 @@
 #![warn(rust_2018_idioms, unused_lifetimes)]
 
 use itertools::Itertools;
-use std::fs::File;
 use std::io::{self, IsTerminal};
 use std::path::PathBuf;
 use std::process::Command;
-use std::time::SystemTime;
 use test_utils::IS_RUSTC_TEST_SUITE;
 use ui_test::Args;
 
@@ -28,11 +26,7 @@ fn main() {
             println!("dogfood: test");
         }
     } else if !args.skip.iter().any(|arg| arg == "dogfood") {
-        if args.filters.iter().any(|arg| arg == "collect_metadata") {
-            collect_metadata();
-        } else {
-            dogfood();
-        }
+        dogfood();
     }
 }
 
@@ -61,47 +55,6 @@ fn dogfood() {
     );
 }
 
-fn collect_metadata() {
-    assert!(cfg!(feature = "internal"));
-
-    // 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");
-    assert!(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;
-                }
-            }
-        }
-    }
-
-    // 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
-    assert!(run_clippy_for_package(
-        "clippy_lints",
-        &["-A", "unfulfilled_lint_expectations"]
-    ));
-}
-
 #[must_use]
 fn run_clippy_for_package(project: &str, args: &[&str]) -> bool {
     let root_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));