Make write_rustdoc_diff a more generic function

Author: Nicholas-Baron

src/tools/compiletest/src/compute_diff.rs

@@ -1,4 +1,5 @@
 use std::collections::VecDeque;
+use std::fs::{File, FileType};
 use std::path::Path;
 
 #[derive(Debug, PartialEq)]
@@ -106,23 +107,26 @@ pub(crate) fn write_diff(expected: &str, actual: &str, context_size: usize) -> S
     output
 }
 
+/// Filters based on filetype and extension whether to diff a file.
+///
 /// Returns whether any data was actually written.
-pub(crate) fn write_rustdoc_diff(
+pub(crate) fn write_filtered_diff<Filter>(
     diff_filename: &str,
     out_dir: &Path,
     compare_dir: &Path,
     verbose: bool,
-) -> bool {
-    use std::fs::File;
+    filter: Filter,
+) -> bool
+where
+    Filter: Fn(FileType, Option<&str>) -> bool,
+{
     use std::io::{Read, Write};
     let mut diff_output = File::create(diff_filename).unwrap();
     let mut wrote_data = false;
     for entry in walkdir::WalkDir::new(out_dir) {
         let entry = entry.expect("failed to read file");
         let extension = entry.path().extension().and_then(|p| p.to_str());
-        if entry.file_type().is_file()
-            && (extension == Some("html".into()) || extension == Some("js".into()))
-        {
+        if filter(entry.file_type(), extension) {
             let expected_path = compare_dir.join(entry.path().strip_prefix(&out_dir).unwrap());
             let expected = if let Ok(s) = std::fs::read(&expected_path) { s } else { continue };
             let actual_path = entry.path();

src/tools/compiletest/src/runtest.rs

@@ -8,7 +8,7 @@ use crate::common::{CompareMode, FailMode, PassMode};
 use crate::common::{Config, TestPaths};
 use crate::common::{Pretty, RunPassValgrind};
 use crate::common::{UI_RUN_STDERR, UI_RUN_STDOUT};
-use crate::compute_diff::{write_diff, write_rustdoc_diff};
+use crate::compute_diff::{write_diff, write_filtered_diff};
 use crate::errors::{self, Error, ErrorKind};
 use crate::header::TestProps;
 use crate::json;
@@ -2403,7 +2403,16 @@ impl<'test> TestCx<'test> {
 
         let diff_filename = format!("build/tmp/rustdoc-compare-{}.diff", std::process::id());
 
-        if !write_rustdoc_diff(&diff_filename, out_dir, &compare_dir, self.config.verbose) {
+        if !write_filtered_diff(
+            &diff_filename,
+            out_dir,
+            &compare_dir,
+            self.config.verbose,
+            |file_type, extension| {
+                file_type.is_file()
+                    && (extension == Some("html".into()) || extension == Some("js".into()))
+            },
+        ) {
             return;
         }