Add use_tabs option to config for indenting with tab characters

Cargo.toml

@@ -12,6 +12,7 @@ categories = ["command-line-utilities", "development-tools"]
 
 [lib]
 name = "typstfmt"
+
 [dependencies]
 lexopt = "0.3.0"
 confy = "0.5.1"
@@ -28,5 +29,6 @@ unicode-width = "0.1.11"
 similar-asserts = "1.4.2"
 insta = "1.30.0"
 tracing-subscriber = "0.3.17"
+
 [[bin]]
 name = "typstfmt"

README.md

@@ -37,6 +37,7 @@ Basic formatter for the Typst language with a future!
   max_line_length = 80
   experimental_args_breaking_consecutive = false
   line_wrap = true
+  use_tabs = false
   ```
 - Disable the formatting by surrounding code with `// typstfmt::off` and `//
   typstfmt::on`. (Experimental and broken)

src/config.rs

@@ -9,6 +9,8 @@ pub struct Config {
     /// If enabled, when breaking arguments, it will try to keep more on one line.
     pub experimental_args_breaking_consecutive: bool,
     pub line_wrap: bool,
+    /// If enabled, `indent_space` will be ignored
+    pub use_tabs: bool,
 }
 
 impl Default for Config {
@@ -19,6 +21,7 @@ impl Default for Config {
             max_line_length: 80,
             line_wrap: true,
             experimental_args_breaking_consecutive: false,
+            use_tabs: false,
         }
     }
 }

src/context.rs

@@ -105,6 +105,10 @@ impl Ctx {
 
     /// returns an indent using config to get it's length.
     pub(crate) fn get_indent(&self) -> String {
-        " ".repeat(self.config.indent_space)
+        if self.config.use_tabs {
+            "\t".to_owned()
+        } else {
+            " ".repeat(self.config.indent_space)
+        }
     }
 }

src/lib.rs

@@ -35,7 +35,11 @@ mod params;
 #[must_use]
 pub fn format(s: &str, config: Config) -> String {
     //replace tabs
-    let s = &s.replace('\t', &" ".repeat(config.indent_space));
+    let s = &if config.use_tabs {
+        s.to_owned()
+    } else {
+        s.replace('\t', &" ".repeat(config.indent_space))
+    };
 
     let init = parse(s);
     let mut context = Ctx::from_config(config);

src/tests/snapshots/typstfmt__tests__snippets__on_off_indent_bug_tab__snapshot.snap

@@ -0,0 +1,6 @@
+---
+source: src/tests/snippets.rs
+description: "INPUT\n===\n\"#let template(doc) = {\\n  //typstfmt::off\\n  let         a      =    \\\"\\\"\\n  //typstfmt::on\\n  doc\\n}\"\n===\n#let template(doc) = {\n  //typstfmt::off\n  let         a      =    \"\"\n  //typstfmt::on\n  doc\n}\n===\nFORMATTED\n===\n#let template(doc) = {\n\t//typstfmt::off\n  let         a      =    \"\"\n  //typstfmt::on\n  doc\n}"
+expression: formatted
+---
+"#let template(doc) = {\n\t//typstfmt::off\n  let         a      =    \"\"\n  //typstfmt::on\n  doc\n}"

src/tests/snippets.rs

@@ -31,6 +31,19 @@ make_test!(
   doc
 }"#
 );
+make_test!(
+    on_off_indent_bug_tab,
+    r#"#let template(doc) = {
+  //typstfmt::off
+  let         a      =    ""
+  //typstfmt::on
+  doc
+}"#,
+    Config {
+        use_tabs: true,
+        ..Default::default()
+    }
+);
 make_test!(official, OFFICIAL);
 make_test!(raw_text, RAW);
 make_test!(tabs, TABS);
@@ -72,6 +85,21 @@ test_eq!(
 ]"
 );
 
+test_eq!(
+    stable_raw_indents_tab,
+    "#focus-slide[
+#fit-to-height(3em)[Introduction]
+
+#pdfpc.speaker-note(```
+    Let's start the introduction with a quote from Foo Bar
+  ```)
+]",
+    Config {
+        use_tabs: true,
+        ..Default::default()
+    }
+);
+
 // TODO: wait for parser fix
 //    $step(&>= ceil(phi.alt (n+1)) / (n+1) >= phi.alt. )$
 // vs $step(&>= ceil(phi.alt (n+1)) / (n+1) >= phi.alt.)$