fix: deny invalid rtk read flags

Author: LK4D4

docs/DEVELOPMENT.md

@@ -85,6 +85,9 @@ Rewrite order:
 ## What It Rewrites
 
 - Already preferred RTK commands are left alone, such as `rtk git status --short`.
+  Invalid `rtk read` forms with invented flags such as `--line`, `--lines`, or
+  `--range` are denied with `rtk read --help` so agents do not confuse RTK parse
+  fallback errors with a missing `rtk read` command.
 - Mutating PowerShell commands are left alone, including `Remove-Item`,
   `Set-Content`, `Add-Content`, `New-Item`, `Move-Item`, and `Copy-Item`.
 - Windows/PowerShell and Unix shell reads/searches are handled locally first.

src/rewrite.rs

@@ -9,22 +9,46 @@ struct Token {
 
 pub fn suggest(command: &str) -> Option<String> {
     let command = command.trim();
-    if command.is_empty()
-        || starts_with_rtk(command) && preferred_rtk_command(command)
-        || is_preferred_pwsh_wrapper(command)
-        || is_preferred_bash_wrapper(command)
+    if command.is_empty() {
+        return None;
+    }
+
+    invalid_rtk_read_redirect(command).or_else(|| {
+        if starts_with_rtk(command) && preferred_rtk_command(command)
+            || is_preferred_pwsh_wrapper(command)
+            || is_preferred_bash_wrapper(command)
+        {
+            return None;
+        }
+
+        direct_powershell_redirect(command)
+            .or_else(|| powershell_redirect(command))
+            .or_else(|| env_redirect(command))
+            .or_else(|| bash_redirect(command))
+            .or_else(|| posix_redirect(command))
+            .or_else(|| rg_redirect(command))
+            .or_else(|| safe_external_rtk_rewrite(command))
+            .or_else(|| local_rtk_miss_fallback(command))
+    })
+}
+
+fn invalid_rtk_read_redirect(command: &str) -> Option<String> {
+    let tokens = tokenize(command);
+    if command_name(&tokens.first()?.text) != "rtk" || command_name(&tokens.get(1)?.text) != "read"
     {
         return None;
     }
 
-    direct_powershell_redirect(command)
-        .or_else(|| powershell_redirect(command))
-        .or_else(|| env_redirect(command))
-        .or_else(|| bash_redirect(command))
-        .or_else(|| posix_redirect(command))
-        .or_else(|| rg_redirect(command))
-        .or_else(|| safe_external_rtk_rewrite(command))
-        .or_else(|| local_rtk_miss_fallback(command))
+    tokens
+        .iter()
+        .skip(2)
+        .any(|token| {
+            matches!(token.text.as_str(), "--line" | "--lines" | "--range")
+                || token.text.starts_with("--line=")
+                || token.text.starts_with("--lines=")
+                || token.text.starts_with("--range=")
+        })
+        .then(|| "rtk read --help".to_string())
 }
 
 fn preferred_rtk_command(command: &str) -> bool {

tests/pretool.rs

@@ -205,11 +205,24 @@ fn already_good_commands_are_noops() {
     assert_no_output("rtk git status --short");
     assert_no_output(r#"rtk grep -n "foo" src"#);
     assert_no_output("rtk find src");
+    assert_no_output("rtk read src/main.rs --max-lines 120");
+    assert_no_output("rtk read -n src/main.rs --tail-lines 40");
     assert_no_output(
         r#"pwsh -NoProfile -Command '$env:PATH="$env:APPDATA\luarocks\bin;$env:PATH"; rtk busted spec'"#,
     );
 }
 
+#[test]
+fn invalid_rtk_read_flags_suggest_help() {
+    for command in [
+        "rtk read suwayomi/client/source_manga.lua --line 1 --lines 650",
+        "rtk read suwayomi/ui.lua --line 1-120",
+        "rtk read suwayomi/ui.lua --range 130:310",
+    ] {
+        assert_deny(command, "rtk read --help");
+    }
+}
+
 #[test]
 fn powershell_mutations_are_noops() {
     for verb in [