Allow excluding cache based on status code (#1403)

This introduces an option `--cache-exclude-status`, which allows specifying a range of HTTP status codes which will be ignored from the cache.

Closes #1400.

README.md

@@ -335,6 +335,22 @@ Options:
 
           [default: 1d]
 
+      --cache-exclude-status <CACHE_EXCLUDE_STATUS>
+          A list of status codes that will be ignored from the cache
+
+          The following accept range syntax is supported: [start]..[=]end|code. Some valid
+          examples are:
+
+          - 429
+          - 500..=599
+          - 500..
+
+          Use "lychee --cache-exclude-status '429, 500..502' <inputs>..." to provide a comma- separated
+          list of excluded status codes. This example will not cache results with a status code of 429, 500,
+          501 and 502.
+
+          [default: ]
+
       --dump
           Don't perform any link checking. Instead, dump all the links extracted from inputs that would be checked
 

lychee-bin/src/commands/check.rs

@@ -10,7 +10,7 @@ use reqwest::Url;
 use tokio::sync::mpsc;
 use tokio_stream::wrappers::ReceiverStream;
 
-use lychee_lib::{Client, ErrorKind, Request, Response};
+use lychee_lib::{Client, ErrorKind, Request, Response, Uri};
 use lychee_lib::{InputSource, Result};
 use lychee_lib::{ResponseBody, Status};
 
@@ -46,6 +46,7 @@ where
 
     let client = params.client;
     let cache = params.cache;
+    let cache_exclude_status = params.cfg.cache_exclude_status.into_set();
     let accept = params.cfg.accept.into_set();
 
     let pb = if params.cfg.no_progress || params.cfg.verbose.log_level() >= log::Level::Info {
@@ -61,6 +62,7 @@ where
         max_concurrency,
         client,
         cache,
+        cache_exclude_status,
         accept,
     ));
 
@@ -219,14 +221,22 @@ async fn request_channel_task(
     max_concurrency: usize,
     client: Client,
     cache: Arc<Cache>,
+    cache_exclude_status: HashSet<u16>,
     accept: HashSet<u16>,
 ) {
     StreamExt::for_each_concurrent(
         ReceiverStream::new(recv_req),
         max_concurrency,
         |request: Result<Request>| async {
             let request = request.expect("cannot read request");
-            let response = handle(&client, cache.clone(), request, accept.clone()).await;
+            let response = handle(
+                &client,
+                cache.clone(),
+                cache_exclude_status.clone(),
+                request,
+                accept.clone(),
+            )
+            .await;
 
             send_resp
                 .send(response)
@@ -260,6 +270,7 @@ async fn check_url(client: &Client, request: Request) -> Response {
 async fn handle(
     client: &Client,
     cache: Arc<Cache>,
+    cache_exclude_status: HashSet<u16>,
     request: Request,
     accept: HashSet<u16>,
 ) -> Response {
@@ -287,16 +298,37 @@ async fn handle(
     //   benefit.
     // - Skip caching unsupported URLs as they might be supported in a
     //   future run.
-    // - Skip caching excluded links; they might not be excluded in the next run
+    // - Skip caching excluded links; they might not be excluded in the next run.
+    // - Skip caching links for which the status code has been explicitly excluded from the cache.
     let status = response.status();
-    if uri.is_file() || status.is_excluded() || status.is_unsupported() || status.is_unknown() {
+    if ignore_cache(&uri, status, &cache_exclude_status) {
         return response;
     }
 
     cache.insert(uri, status.into());
     response
 }
 
+/// Returns `true` if the response should be ignored in the cache.
+///
+/// The response should be ignored if:
+/// - The URI is a file URI.
+/// - The status is excluded.
+/// - The status is unsupported.
+/// - The status is unknown.
+/// - The status code is excluded from the cache.
+fn ignore_cache(uri: &Uri, status: &Status, cache_exclude_status: &HashSet<u16>) -> bool {
+    let status_code_excluded = status
+        .code()
+        .map_or(false, |code| cache_exclude_status.contains(&code.as_u16()));
+
+    uri.is_file()
+        || status.is_excluded()
+        || status.is_unsupported()
+        || status.is_unknown()
+        || status_code_excluded
+}
+
 fn show_progress(
     output: &mut dyn Write,
     progress_bar: &Option<ProgressBar>,
@@ -344,8 +376,9 @@ fn get_failed_urls(stats: &mut ResponseStats) -> Vec<(InputSource, Url)> {
 #[cfg(test)]
 mod tests {
     use crate::{formatters::get_response_formatter, options};
+    use http::StatusCode;
     use log::info;
-    use lychee_lib::{CacheStatus, ClientBuilder, InputSource, Uri};
+    use lychee_lib::{CacheStatus, ClientBuilder, ErrorKind, InputSource, Uri};
 
     use super::*;
 
@@ -406,4 +439,55 @@ mod tests {
             Status::Error(ErrorKind::InvalidURI(_))
         ));
     }
+
+    #[test]
+    fn test_cache_by_default() {
+        assert!(!ignore_cache(
+            &Uri::try_from("https://[::1]").unwrap(),
+            &Status::Ok(StatusCode::OK),
+            &HashSet::default()
+        ));
+    }
+
+    #[test]
+    // Cache is ignored for file URLs
+    fn test_cache_ignore_file_urls() {
+        assert!(ignore_cache(
+            &Uri::try_from("file:///home").unwrap(),
+            &Status::Ok(StatusCode::OK),
+            &HashSet::default()
+        ));
+    }
+
+    #[test]
+    // Cache is ignored for unsupported status
+    fn test_cache_ignore_unsupported_status() {
+        assert!(ignore_cache(
+            &Uri::try_from("https://[::1]").unwrap(),
+            &Status::Unsupported(ErrorKind::EmptyUrl),
+            &HashSet::default()
+        ));
+    }
+
+    #[test]
+    // Cache is ignored for unknown status
+    fn test_cache_ignore_unknown_status() {
+        assert!(ignore_cache(
+            &Uri::try_from("https://[::1]").unwrap(),
+            &Status::UnknownStatusCode(StatusCode::IM_A_TEAPOT),
+            &HashSet::default()
+        ));
+    }
+
+    #[test]
+    fn test_cache_ignore_excluded_status() {
+        // Cache is ignored for excluded status codes
+        let exclude = [StatusCode::OK.as_u16()].iter().copied().collect();
+
+        assert!(ignore_cache(
+            &Uri::try_from("https://[::1]").unwrap(),
+            &Status::Ok(StatusCode::OK),
+            &exclude
+        ));
+    }
 }

lychee-bin/src/options.rs

@@ -6,8 +6,8 @@ use clap::builder::PossibleValuesParser;
 use clap::{arg, builder::TypedValueParser, Parser};
 use const_format::{concatcp, formatcp};
 use lychee_lib::{
-    AcceptSelector, Base, BasicAuthSelector, Input, DEFAULT_MAX_REDIRECTS, DEFAULT_MAX_RETRIES,
-    DEFAULT_RETRY_WAIT_TIME_SECS, DEFAULT_TIMEOUT_SECS, DEFAULT_USER_AGENT,
+    Base, BasicAuthSelector, Input, StatusCodeExcluder, StatusCodeSelector, DEFAULT_MAX_REDIRECTS,
+    DEFAULT_MAX_RETRIES, DEFAULT_RETRY_WAIT_TIME_SECS, DEFAULT_TIMEOUT_SECS, DEFAULT_USER_AGENT,
 };
 use secrecy::{ExposeSecret, SecretString};
 use serde::Deserialize;
@@ -145,7 +145,8 @@ default_function! {
     retry_wait_time: usize = DEFAULT_RETRY_WAIT_TIME_SECS;
     method: String = DEFAULT_METHOD.to_string();
     verbosity: Verbosity = Verbosity::default();
-    accept_selector: AcceptSelector = AcceptSelector::default();
+    cache_exclude_selector: StatusCodeExcluder = StatusCodeExcluder::new();
+    accept_selector: StatusCodeSelector = StatusCodeSelector::default();
 }
 
 // Macro for merging configuration values
@@ -231,6 +232,26 @@ pub(crate) struct Config {
     #[serde(with = "humantime_serde")]
     pub(crate) max_cache_age: Duration,
 
+    /// A list of status codes that will be excluded from the cache
+    #[arg(
+        long,
+        default_value_t,
+        long_help = "A list of status codes that will be ignored from the cache
+
+The following accept range syntax is supported: [start]..[=]end|code. Some valid
+examples are:
+
+- 429
+- 500..=599
+- 500..
+
+Use \"lychee --cache-exclude-status '429, 500..502' <inputs>...\" to provide a comma- separated
+list of excluded status codes. This example will not cache results with a status code of 429, 500,
+501 and 502."
+    )]
+    #[serde(default = "cache_exclude_selector")]
+    pub(crate) cache_exclude_status: StatusCodeExcluder,
+
     /// Don't perform any link checking.
     /// Instead, dump all the links extracted from inputs that would be checked
     #[arg(long)]
@@ -394,7 +415,7 @@ separated list of accepted status codes. This example will accept 200, 201,
 202, 203, 204, 429, and 500 as valid status codes."
     )]
     #[serde(default = "accept_selector")]
-    pub(crate) accept: AcceptSelector,
+    pub(crate) accept: StatusCodeSelector,
 
     /// Enable the checking of fragments in links.
     #[arg(long)]
@@ -509,6 +530,7 @@ impl Config {
             max_retries: DEFAULT_MAX_RETRIES;
             max_concurrency: DEFAULT_MAX_CONCURRENCY;
             max_cache_age: humantime::parse_duration(DEFAULT_MAX_CACHE_AGE).unwrap();
+            cache_exclude_status: StatusCodeExcluder::default();
             threads: None;
             user_agent: DEFAULT_USER_AGENT;
             insecure: false;
@@ -538,7 +560,7 @@ impl Config {
             require_https: false;
             cookie_jar: None;
             include_fragments: false;
-            accept: AcceptSelector::default();
+            accept: StatusCodeSelector::default();
         }
 
         if self
@@ -564,7 +586,7 @@ mod tests {
     #[test]
     fn test_accept_status_codes() {
         let toml = Config {
-            accept: AcceptSelector::from_str("200..=204, 429, 500").unwrap(),
+            accept: StatusCodeSelector::from_str("200..=204, 429, 500").unwrap(),
             ..Default::default()
         };
 
@@ -577,4 +599,15 @@ mod tests {
         assert!(cli.accept.contains(204));
         assert!(!cli.accept.contains(205));
     }
+
+    #[test]
+    fn test_default() {
+        let cli = Config::default();
+
+        assert_eq!(
+            cli.accept,
+            StatusCodeSelector::from_str("100..=103,200..=299").expect("no error")
+        );
+        assert_eq!(cli.cache_exclude_status, StatusCodeExcluder::new());
+    }
 }

lychee-bin/tests/cli.rs

@@ -895,6 +895,65 @@ mod cli {
         Ok(())
     }
 
+    #[tokio::test]
+    async fn test_lycheecache_exclude_custom_status_codes() -> Result<()> {
+        let base_path = fixtures_path().join("cache");
+        let cache_file = base_path.join(LYCHEE_CACHE_FILE);
+
+        // Unconditionally remove cache file if it exists
+        let _ = fs::remove_file(&cache_file);
+
+        let mock_server_ok = mock_server!(StatusCode::OK);
+        let mock_server_no_content = mock_server!(StatusCode::NO_CONTENT);
+        let mock_server_too_many_requests = mock_server!(StatusCode::TOO_MANY_REQUESTS);
+
+        let dir = tempfile::tempdir()?;
+        let mut file = File::create(dir.path().join("c.md"))?;
+
+        writeln!(file, "{}", mock_server_ok.uri().as_str())?;
+        writeln!(file, "{}", mock_server_no_content.uri().as_str())?;
+        writeln!(file, "{}", mock_server_too_many_requests.uri().as_str())?;
+
+        let mut cmd = main_command();
+        let test_cmd = cmd
+            .current_dir(&base_path)
+            .arg(dir.path().join("c.md"))
+            .arg("--verbose")
+            .arg("--no-progress")
+            .arg("--cache")
+            .arg("--cache-exclude-status")
+            .arg("204,429");
+
+        assert!(
+            !cache_file.exists(),
+            "cache file should not exist before this test"
+        );
+
+        // run first without cache to generate the cache file
+        test_cmd
+            .assert()
+            .stderr(contains(format!("[200] {}/\n", mock_server_ok.uri())))
+            .stderr(contains(format!(
+                "[204] {}/ | OK (204 No Content): No Content\n",
+                mock_server_no_content.uri()
+            )))
+            .stderr(contains(format!(
+                "[429] {}/ | Failed: Network error: Too Many Requests\n",
+                mock_server_too_many_requests.uri()
+            )));
+
+        // check content of cache file
+        let data = fs::read_to_string(&cache_file)?;
+        assert!(data.contains(&format!("{}/,200", mock_server_ok.uri())));
+        assert!(!data.contains(&format!("{}/,204", mock_server_no_content.uri())));
+        assert!(!data.contains(&format!("{}/,429", mock_server_too_many_requests.uri())));
+
+        // clear the cache file
+        fs::remove_file(&cache_file)?;
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn test_lycheecache_accept_custom_status_codes() -> Result<()> {
         let base_path = fixtures_path().join("cache_accept_custom_status_codes");

lychee-lib/src/lib.rs

@@ -95,8 +95,9 @@ pub use crate::{
     collector::Collector,
     filter::{Excludes, Filter, Includes},
     types::{
-        uri::valid::Uri, AcceptRange, AcceptRangeError, AcceptSelector, Base, BasicAuthCredentials,
+        uri::valid::Uri, AcceptRange, AcceptRangeError, Base, BasicAuthCredentials,
         BasicAuthSelector, CacheStatus, CookieJar, ErrorKind, FileType, Input, InputContent,
-        InputSource, Request, Response, ResponseBody, Result, Status,
+        InputSource, Request, Response, ResponseBody, Result, Status, StatusCodeExcluder,
+        StatusCodeSelector,
     },
 };

lychee-lib/src/types/accept/mod.rs

@@ -1,5 +1,3 @@
 mod range;
-mod selector;
 
 pub use range::*;
-pub use selector::*;

lychee-lib/src/types/accept/range.rs

@@ -7,8 +7,8 @@ use thiserror::Error;
 static RANGE_PATTERN: Lazy<Regex> =
     Lazy::new(|| Regex::new(r"^([0-9]{3})?\.\.(=?)([0-9]{3})+$|^([0-9]{3})$").unwrap());
 
-/// The [`AcceptRangeParseError`] indicates that the parsing process of an
-/// [`AcceptRange`]  from a string failed due to various underlying reasons.
+/// Indicates that the parsing process of an [`AcceptRange`]  from a string
+/// failed due to various underlying reasons.
 #[derive(Debug, Error, PartialEq)]
 pub enum AcceptRangeError {
     /// The string input didn't contain any range pattern.