fix: avoid nested BufReader and serve tealdeer page without cache

pages/tealdeer.md

@@ -5,12 +5,6 @@
 
 > This page shows tealdeer specific functionality. See tldr tldr for more examples.
 
-`tldr --update`
-
-- List all pages in the cache:
-
-`tldr --list`
-
 - Render a local markdown file as a tldr page:
 
 `tldr --render {{path/to/file.md}}`
@@ -27,6 +21,10 @@
 
 `tldr --seed-config`
 
+- Override config file location:
+
+`tldr --config-path <FILE>`
+
 - Open a custom page for a command in `$EDITOR` (creates it if it doesn't exist):
 
 `tldr --edit-page {{command}}`
@@ -38,3 +36,7 @@
 - Clear the local cache:
 
 `tldr --clear-cache`
+
+- If auto update is configured, disable it for this run:
+
+`tldr --no-auto-update`

src/cache.rs

@@ -1,6 +1,6 @@
 use std::{
     fs::{self, File},
-    io::{BufReader, Cursor, ErrorKind, Read},
+    io::{Cursor, ErrorKind, Read},
     path::{Path, PathBuf},
     time::{Duration, SystemTime},
 };
@@ -277,12 +277,12 @@ impl PageLookupResult {
         self
     }
 
-    /// Create a buffered reader that sequentially reads from the page and the
+    /// Create a reader that sequentially reads from the page and the
     /// patch, as if they were concatenated.
     ///
     /// This will return an error if either the page file or the patch file
     /// cannot be opened.
-    pub fn reader(&self) -> Result<BufReader<Box<dyn Read>>> {
+    pub fn reader(&self) -> Result<Box<dyn Read>> {
         // Open page file
         let page_file = File::open(&self.page_path)
             .with_context(|| format!("Could not open page file at {}", self.page_path.display()))?;
@@ -302,11 +302,11 @@ impl PageLookupResult {
         // the page and patch files and that will read them sequentially,
         // because it avoids the boxing below. However, the performance impact
         // would first need to be shown to be significant using a benchmark.
-        Ok(BufReader::new(if let Some(patch_file) = patch_file_opt {
+        Ok(if let Some(patch_file) = patch_file_opt {
             Box::new(page_file.chain(&b"\n"[..]).chain(patch_file)) as Box<dyn Read>
         } else {
             Box::new(page_file) as Box<dyn Read>
-        }))
+        })
     }
 }
 

src/main.rs

@@ -265,6 +265,18 @@ fn try_main(args: Cli, enable_styles: bool) -> Result<ExitCode> {
         return Ok(ExitCode::SUCCESS);
     }
 
+    // The tealdeer page is embedded in the binary, no cache needed
+    if command == "tealdeer" {
+        print_page(
+            Cursor::new(TEALDEER_PAGE.as_bytes()),
+            args.raw,
+            enable_styles,
+            args.pager,
+            &config,
+        )?;
+        return Ok(ExitCode::SUCCESS);
+    }
+
     if let Some(platforms) = args.platforms {
         config.search.platforms = platforms;
         if !config.search.platforms.contains(&PlatformType::Common) {
@@ -409,27 +421,28 @@ fn try_main(args: Cli, enable_styles: bool) -> Result<ExitCode> {
             );
         }
 
-        let reader: Box<dyn io::Read> = if command == "tealdeer" {
-            Box::new(Cursor::new(TEALDEER_PAGE.as_bytes()))
-        } else {
-            let Some(result) = cache.find_page(&command) else {
-                if !args.quiet {
-                    print_warning(
-                        enable_styles,
-                        &format!(
-                            "Page `{}` not found in cache.\n\
-                       Try updating with `tldr --update`, or submit a pull request to:\n\
-                       https://github.com/tldr-pages/tldr",
-                            &command
-                        ),
-                    );
-                }
-                return Ok(ExitCode::FAILURE);
-            };
-            Box::new(result.reader()?)
+        let Some(result) = cache.find_page(&command) else {
+            if !args.quiet {
+                print_warning(
+                    enable_styles,
+                    &format!(
+                        "Page `{}` not found in cache.\n\
+                         Try updating with `tldr --update`, or submit a pull request to:\n\
+                         https://github.com/tldr-pages/tldr",
+                        &command
+                    ),
+                );
+            }
+            return Ok(ExitCode::FAILURE);
         };
 
-        print_page(reader, args.raw, enable_styles, args.pager, &config)?;
+        print_page(
+            result.reader()?,
+            args.raw,
+            enable_styles,
+            args.pager,
+            &config,
+        )?;
     }
 
     Ok(ExitCode::SUCCESS)

tests/lib.rs

@@ -301,6 +301,16 @@ fn test_missing_cache() {
         .stderr(contains("Page cache not found. Please run `tldr --update`"));
 }
 
+#[test]
+fn test_tealdeer_page_works_without_cache() {
+    TestEnv::new()
+        .command()
+        .args(["tealdeer"])
+        .assert()
+        .success()
+        .stdout(contains("for your installed tealdeer version"));
+}
+
 #[cfg_attr(feature = "ignore-online-tests", ignore = "online test")]
 #[test]
 fn test_update_cache_default_features() {