fix: cache paths on Windows are broken (#2760)

cli/disk_cache.rs

@@ -1,8 +1,11 @@
 use crate::fs as deno_fs;
 use std::ffi::OsStr;
 use std::fs;
+use std::path::Component;
 use std::path::Path;
 use std::path::PathBuf;
+use std::path::Prefix;
+use std::str;
 use url::Url;
 
 #[derive(Clone)]
@@ -18,15 +21,12 @@ impl DiskCache {
     }
   }
 
-  // TODO(bartlomieju) this method is not working properly for Windows paths,
-  // Example: file:///C:/deno/js/unit_test_runner.ts
-  // would produce: C:deno\\js\\unit_test_runner.ts
-  // it should produce: file\deno\js\unit_test_runner.ts
   pub fn get_cache_filename(self: &Self, url: &Url) -> PathBuf {
     let mut out = PathBuf::new();
 
     let scheme = url.scheme();
     out.push(scheme);
+
     match scheme {
       "http" | "https" => {
         let host = url.host_str().unwrap();
@@ -37,13 +37,48 @@ impl DiskCache {
           None => host.to_string(),
         };
         out.push(host_port);
+
+        for path_seg in url.path_segments().unwrap() {
+          out.push(path_seg);
+        }
+      }
+      "file" => {
+        let path = url.to_file_path().unwrap();
+        let mut path_components = path.components();
+
+        if cfg!(target_os = "windows") {
+          if let Some(Component::Prefix(prefix_component)) =
+            path_components.next()
+          {
+            // Windows doesn't support ":" in filenames, so we need to extract disk prefix
+            // Example: file:///C:/deno/js/unit_test_runner.ts
+            // it should produce: file\c\deno\js\unit_test_runner.ts
+            match prefix_component.kind() {
+              Prefix::Disk(disk_byte) | Prefix::VerbatimDisk(disk_byte) => {
+                let disk = (disk_byte as char).to_string();
+                out.push(disk);
+              }
+              _ => unreachable!(),
+            }
+          }
+        }
+
+        // Must be relative, so strip forward slash
+        let mut remaining_components = path_components.as_path();
+        if let Ok(stripped) = remaining_components.strip_prefix("/") {
+          remaining_components = stripped;
+        };
+
+        out = out.join(remaining_components);
+      }
+      scheme => {
+        unimplemented!(
+          "Don't know how to create cache name for scheme: {}",
+          scheme
+        );
       }
-      _ => {}
     };
 
-    for path_seg in url.path_segments().unwrap() {
-      out.push(path_seg);
-    }
     out
   }
 
@@ -90,9 +125,15 @@ mod tests {
 
   #[test]
   fn test_get_cache_filename() {
-    let cache = DiskCache::new(&PathBuf::from("foo"));
+    let cache_location = if cfg!(target_os = "windows") {
+      PathBuf::from(r"C:\deno_dir\")
+    } else {
+      PathBuf::from("/deno_dir/")
+    };
+
+    let cache = DiskCache::new(&cache_location);
 
-    let test_cases = [
+    let mut test_cases = vec![
       (
         "http://deno.land/std/http/file_server.ts",
         "http/deno.land/std/http/file_server.ts",
@@ -105,42 +146,55 @@ mod tests {
         "https://deno.land/std/http/file_server.ts",
         "https/deno.land/std/http/file_server.ts",
       ),
-      (
+    ];
+
+    if cfg!(target_os = "windows") {
+      test_cases.push(("file:///D:/a/1/s/format.ts", "file/D/a/1/s/format.ts"));
+    } else {
+      test_cases.push((
         "file:///std/http/file_server.ts",
         "file/std/http/file_server.ts",
-      ),
-    ];
+      ));
+    }
 
     for test_case in &test_cases {
-      assert_eq!(
-        cache.get_cache_filename(&Url::parse(test_case.0).unwrap()),
-        PathBuf::from(test_case.1)
-      )
+      let cache_filename =
+        cache.get_cache_filename(&Url::parse(test_case.0).unwrap());
+      assert_eq!(cache_filename, PathBuf::from(test_case.1));
     }
   }
 
   #[test]
   fn test_get_cache_filename_with_extension() {
     let cache = DiskCache::new(&PathBuf::from("foo"));
 
-    let test_cases = [
+    let mut test_cases = vec![
       (
         "http://deno.land/std/http/file_server.ts",
         "js",
         "http/deno.land/std/http/file_server.ts.js",
       ),
-      (
-        "file:///std/http/file_server",
-        "js",
-        "file/std/http/file_server.js",
-      ),
       (
         "http://deno.land/std/http/file_server.ts",
         "js.map",
         "http/deno.land/std/http/file_server.ts.js.map",
       ),
     ];
 
+    if cfg!(target_os = "windows") {
+      test_cases.push((
+        "file:///D:/std/http/file_server",
+        "js",
+        "file/D/std/http/file_server.js",
+      ));
+    } else {
+      test_cases.push((
+        "file:///std/http/file_server",
+        "js",
+        "file/std/http/file_server.js",
+      ));
+    }
+
     for test_case in &test_cases {
       assert_eq!(
         cache.get_cache_filename_with_extension(