fix `:indent-style` crash (#9087)

* removing unreachable statement in `:indent-style`

* update checks when setting indent line and update docs

* `cargo xtask docgen`

book/src/generated/typable-cmd.md

@@ -17,7 +17,7 @@
 | `:write-buffer-close!`, `:wbc!` | Force write changes to disk creating necessary subdirectories and closes the buffer. Accepts an optional path (:write-buffer-close! some/path.txt) |
 | `:new`, `:n` | Create a new scratch buffer. |
 | `:format`, `:fmt` | Format the file using the LSP formatter. |
-| `:indent-style` | Set the indentation style for editing. ('t' for tabs or 1-8 for number of spaces.) |
+| `:indent-style` | Set the indentation style for editing. ('t' for tabs or 1-16 for number of spaces.) |
 | `:line-ending` | Set the document's default line ending. Options: crlf, lf. |
 | `:earlier`, `:ear` | Jump back to an earlier point in edit history. Accepts a number of steps or a time span. |
 | `:later`, `:lat` | Jump to a later point in edit history. Accepts a number of steps or a time span. |

helix-core/src/indent.rs

@@ -22,7 +22,7 @@ pub enum IndentStyle {
 
 // 16 spaces
 const INDENTS: &str = "                ";
-const MAX_INDENT: u8 = 16;
+pub const MAX_INDENT: u8 = 16;
 
 impl IndentStyle {
     /// Creates an `IndentStyle` from an indentation string.

helix-term/src/commands/typed.rs

@@ -6,6 +6,7 @@ use crate::job::Job;
 use super::*;
 
 use helix_core::fuzzy::fuzzy_match;
+use helix_core::indent::MAX_INDENT;
 use helix_core::{encoding, line_ending, path::get_canonicalized_path, shellwords::Shellwords};
 use helix_lsp::{OffsetEncoding, Url};
 use helix_view::document::DEFAULT_LANGUAGE_NAME;
@@ -476,8 +477,7 @@ fn set_indent_style(
         cx.editor.set_status(match style {
             Tabs => "tabs".to_owned(),
             Spaces(1) => "1 space".to_owned(),
-            Spaces(n) if (2..=8).contains(&n) => format!("{} spaces", n),
-            _ => unreachable!(), // Shouldn't happen.
+            Spaces(n) => format!("{} spaces", n),
         });
         return Ok(());
     }
@@ -489,7 +489,7 @@ fn set_indent_style(
         Some(arg) => arg
             .parse::<u8>()
             .ok()
-            .filter(|n| (1..=8).contains(n))
+            .filter(|n| (1..=MAX_INDENT).contains(n))
             .map(Spaces),
         _ => None,
     };
@@ -2606,7 +2606,7 @@ pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
     TypableCommand {
         name: "indent-style",
         aliases: &[],
-        doc: "Set the indentation style for editing. ('t' for tabs or 1-8 for number of spaces.)",
+        doc: "Set the indentation style for editing. ('t' for tabs or 1-16 for number of spaces.)",
         fun: set_indent_style,
         signature: CommandSignature::none(),
     },