feat: --reload flag to take arg for partial reload (#3109)

Example: To reload only std modules --reload=https://deno.land/std/

4 files changed, 147 insertions, 3 deletions

diff --git a/cli/file_fetcher.rs b/cli/file_fetcher.rs
index 29fe04d8a..99ea61795 100644
--- a/cli/file_fetcher.rs
+++ b/cli/file_fetcher.rs
@@ -70,6 +70,7 @@ pub struct SourceFileFetcher {
   deps_cache: DiskCache,
   progress: Progress,
   source_file_cache: SourceFileCache,
+  cache_blacklist: Vec<String>,
   use_disk_cache: bool,
   no_remote_fetch: bool,
 }
@@ -79,12 +80,14 @@ impl SourceFileFetcher {
     deps_cache: DiskCache,
     progress: Progress,
     use_disk_cache: bool,
+    cache_blacklist: Vec<String>,
     no_remote_fetch: bool,
   ) -> std::io::Result<Self> {
     let file_fetcher = Self {
       deps_cache,
       progress,
       source_file_cache: SourceFileCache::default(),
+      cache_blacklist,
       use_disk_cache,
       no_remote_fetch,
     };
@@ -308,8 +311,10 @@ impl SourceFileFetcher {
       return Box::new(futures::future::err(too_many_redirects()));
     }
 
+    let is_blacklisted =
+      check_cache_blacklist(module_url, self.cache_blacklist.as_ref());
     // First try local cache
-    if use_disk_cache {
+    if use_disk_cache && !is_blacklisted {
       match self.fetch_cached_remote_source(&module_url) {
         Ok(Some(source_file)) => {
           return Box::new(futures::future::ok(source_file));
@@ -552,6 +557,26 @@ fn filter_shebang(bytes: Vec<u8>) -> Vec<u8> {
   }
 }
 
+fn check_cache_blacklist(url: &Url, black_list: &[String]) -> bool {
+  let mut url_without_fragmets = url.clone();
+  url_without_fragmets.set_fragment(None);
+  if black_list.contains(&String::from(url_without_fragmets.as_str())) {
+    return true;
+  }
+  let mut url_without_query_strings = url_without_fragmets;
+  url_without_query_strings.set_query(None);
+  let mut path_buf = PathBuf::from(url_without_query_strings.as_str());
+  loop {
+    if black_list.contains(&String::from(path_buf.to_str().unwrap())) {
+      return true;
+    }
+    if !path_buf.pop() {
+      break;
+    }
+  }
+  false
+}
+
 #[derive(Debug, Default)]
 /// Header metadata associated with a particular "symbolic" source code file.
 /// (the associated source code file might not be cached, while remaining
@@ -636,6 +661,7 @@ mod tests {
       DiskCache::new(&dir_path.to_path_buf().join("deps")),
       Progress::new(),
       true,
+      vec![],
       false,
     )
     .expect("setup fail")
@@ -658,6 +684,65 @@ mod tests {
   }
 
   #[test]
+  fn test_cache_blacklist() {
+    let args = crate::flags::resolve_urls(vec![
+      String::from("http://deno.land/std"),
+      String::from("http://github.com/example/mod.ts"),
+      String::from("http://fragment.com/mod.ts#fragment"),
+      String::from("http://query.com/mod.ts?foo=bar"),
+      String::from("http://queryandfragment.com/mod.ts?foo=bar#fragment"),
+    ]);
+
+    let u: Url = "http://deno.land/std/fs/mod.ts".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://github.com/example/file.ts".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), false);
+
+    let u: Url = "http://github.com/example/mod.ts".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://github.com/example/mod.ts?foo=bar".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://github.com/example/mod.ts#fragment".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://fragment.com/mod.ts".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://query.com/mod.ts".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), false);
+
+    let u: Url = "http://fragment.com/mod.ts#fragment".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://query.com/mod.ts?foo=bar".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://queryandfragment.com/mod.ts".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), false);
+
+    let u: Url = "http://queryandfragment.com/mod.ts?foo=bar"
+      .parse()
+      .unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://queryandfragment.com/mod.ts#fragment"
+      .parse()
+      .unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), false);
+
+    let u: Url = "http://query.com/mod.ts?foo=bar#fragment".parse().unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+
+    let u: Url = "http://fragment.com/mod.ts?foo=bar#fragment"
+      .parse()
+      .unwrap();
+    assert_eq!(check_cache_blacklist(&u, &args), true);
+  }
+
+  #[test]
   fn test_source_code_headers_get_and_save() {
     let (_temp_dir, fetcher) = test_setup();
     let url = Url::parse("http://example.com/f.js").unwrap();
diff --git a/cli/flags.rs b/cli/flags.rs
index 8690ac983..612415ec7 100644
--- a/cli/flags.rs
+++ b/cli/flags.rs
@@ -11,6 +11,7 @@ use log::Level;
 use std;
 use std::str;
 use std::str::FromStr;
+use url::Url;
 
 macro_rules! std_url {
   ($x:expr) => {
@@ -45,6 +46,7 @@ pub struct DenoFlags {
   pub import_map_path: Option<String>,
   pub allow_read: bool,
   pub read_whitelist: Vec<String>,
+  pub cache_blacklist: Vec<String>,
   pub allow_write: bool,
   pub write_whitelist: Vec<String>,
   pub allow_net: bool,
@@ -172,8 +174,20 @@ To get help on the another subcommands (run in this case):
     ).arg(
       Arg::with_name("reload")
         .short("r")
+        .min_values(0)
+        .takes_value(true)
+        .use_delimiter(true)
+        .require_equals(true)
         .long("reload")
         .help("Reload source code cache (recompile TypeScript)")
+        .value_name("CACHE_BLACKLIST")
+        .long_help("Reload source code cache (recompile TypeScript)
+          --reload
+            Reload everything
+          --reload=https://deno.land/std
+            Reload all standard modules
+          --reload=https://deno.land/std/fs/utils.ts,https://deno.land/std/fmt/colors.ts
+            Reloads specific modules")
         .global(true),
     ).arg(
       Arg::with_name("config")
@@ -509,6 +523,23 @@ fn resolve_paths(paths: Vec<String>) -> Vec<String> {
   out
 }
 
+pub fn resolve_urls(urls: Vec<String>) -> Vec<String> {
+  let mut out: Vec<String> = vec![];
+  for urlstr in urls.iter() {
+    let result = Url::from_str(urlstr);
+    if result.is_err() {
+      panic!("Bad Url: {}", urlstr);
+    }
+    let mut url = result.unwrap();
+    url.set_fragment(None);
+    let mut full_url = String::from(url.as_str());
+    if full_url.len() > 1 && full_url.ends_with('/') {
+      full_url.pop();
+    }
+    out.push(full_url);
+  }
+  out
+}
 /// This function expands "bare port" paths (eg. ":8080")
 /// into full paths with hosts. It expands to such paths
 /// into 3 paths with following hosts: `0.0.0.0:port`, `127.0.0.1:port` and `localhost:port`.
@@ -566,7 +597,16 @@ pub fn parse_flags(
     flags.version = true;
   }
   if matches.is_present("reload") {
-    flags.reload = true;
+    if matches.value_of("reload").is_some() {
+      let cache_bl = matches.values_of("reload").unwrap();
+      let raw_cache_blacklist: Vec<String> =
+        cache_bl.map(std::string::ToString::to_string).collect();
+      flags.cache_blacklist = resolve_urls(raw_cache_blacklist);
+      debug!("cache blacklist: {:#?}", &flags.cache_blacklist);
+      flags.reload = false;
+    } else {
+      flags.reload = true;
+    }
   }
   flags.config_path = matches.value_of("config").map(ToOwned::to_owned);
   if matches.is_present("v8-options") {
diff --git a/cli/state.rs b/cli/state.rs
index 70845fb8b..950bdba70 100644
--- a/cli/state.rs
+++ b/cli/state.rs
@@ -225,6 +225,7 @@ impl ThreadSafeState {
       dir.deps_cache.clone(),
       progress.clone(),
       !flags.reload,
+      flags.cache_blacklist.clone(),
       flags.no_fetch,
     )?;
 
diff --git a/website/manual.md b/website/manual.md
index b56c93761..ec5612372 100644
--- a/website/manual.md
+++ b/website/manual.md
@@ -381,6 +381,24 @@ And if you ever want to upgrade to the latest published version:
 $ file_server --reload
 ```
 
+### Reload specific modules
+
+Sometimes we want to upgrade only some modules. You can control it by passing an
+argument to a `--reload` flag.
+
+To reload everything
+
+`--reload`
+
+To reload all standard modules
+
+`--reload=https://deno.land/std`
+
+To reload specific modules (in this example - colors and file system utils) use
+a comma to separate URLs
+
+`--reload=https://deno.land/std/fs/utils.ts,https://deno.land/std/fmt/colors.ts`
+
 ### Permissions whitelist
 
 Deno also provides permissions whitelist.
@@ -670,7 +688,7 @@ OPTIONS:
     -L, --log-level <log-level>        Set log level [possible values: debug, info]
         --no-fetch                     Do not download remote modules
         --no-prompt                    Do not use prompts
-    -r, --reload                       Reload source code cache (recompile TypeScript)
+    -r, --reload=<CACHE_BLACKLIST>     Reload source code cache (recompile TypeScript)
         --seed <NUMBER>                Seed Math.random()
         --v8-flags=<v8-flags>          Set V8 command line options
         --v8-options                   Print V8 command line options