fmt: initial test using tiny_pretty

Cargo.toml

@@ -31,6 +31,7 @@ serde_repr = "0.1"
 regex = "1.11.1"
 simplelog = "0.12.0"
 tempfile = "3.21.0"
+tiny_pretty = "0.2.1"
 toml = "0.5.9"
 dir-test = "0.4"
 drop_bomb = "0.1.5"

crates/squawk_fmt/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "squawk-fmt"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+authors.workspace = true
+license.workspace = true
+description.workspace = true
+documentation.workspace = true
+homepage.workspace = true
+repository.workspace = true
+
+[dependencies]
+tiny_pretty.workspace = true
+itertools.workspace = true
+squawk-syntax.workspace = true
+
+[dev-dependencies]
+insta.workspace = true
+
+[lints]
+workspace = true

crates/squawk_fmt/src/lib.rs

@@ -0,0 +1,143 @@
+use itertools::Itertools;
+use squawk_syntax::ast::{self, AstNode};
+use tiny_pretty::Doc;
+use tiny_pretty::{PrintOptions, print};
+
+fn build_source_file(source_file: &ast::SourceFile) -> Doc<'_> {
+    let mut doc = Doc::nil();
+    for stmt in source_file.stmts() {
+        match stmt {
+            ast::Stmt::Select(select) => {
+                doc = doc.append(build_select_doc(select));
+            }
+            ast::Stmt::CreateTable(create_table) => {
+                doc = doc.append(build_create_table(create_table))
+            }
+            _ => (),
+        }
+        doc = doc
+            .append(Doc::text(";"))
+            .append(Doc::empty_line())
+            .append(Doc::empty_line());
+    }
+    doc
+}
+
+fn build_create_table<'a>(create_table: ast::CreateTable) -> Doc<'a> {
+    Doc::text("create")
+        .append(Doc::space())
+        .append(Doc::text("table"))
+        .append(Doc::space())
+        .append(Doc::text(
+            create_table.path().map(|x| x.syntax().to_string()).unwrap(),
+        ))
+        .append(Doc::text("("))
+        .append(
+            Doc::line_or_nil()
+                .append(Doc::list(
+                    Itertools::intersperse(
+                        create_table
+                            .table_arg_list()
+                            .unwrap()
+                            .args()
+                            .map(build_table_arg),
+                        Doc::text(",").append(Doc::line_or_space()),
+                    )
+                    .collect(),
+                ))
+                .nest(2)
+                .append(Doc::line_or_nil())
+                .group(),
+        )
+        .append(Doc::text(")"))
+}
+
+fn build_table_arg<'a>(create_table: ast::TableArg) -> Doc<'a> {
+    match create_table {
+        ast::TableArg::Column(column) => Doc::text(column.name().unwrap().syntax().to_string())
+            .append(Doc::space())
+            .append(Doc::text(column.ty().unwrap().syntax().to_string())),
+        ast::TableArg::LikeClause(_like_clause) => todo!(),
+        ast::TableArg::TableConstraint(_table_constraint) => todo!(),
+    }
+}
+
+fn build_select_doc<'a>(select: ast::Select) -> Doc<'a> {
+    let mut doc = Doc::text("select").append(Doc::space());
+
+    if let Some(targets) = select
+        .select_clause()
+        .and_then(|x| x.target_list())
+        .map(|x| x.targets())
+    {
+        doc = doc
+            .append(
+                Doc::line_or_nil().append(Doc::list(
+                    Itertools::intersperse(
+                        targets.flat_map(|x| Some(Doc::text(x.expr()?.syntax().to_string()))),
+                        Doc::text(",").append(Doc::line_or_space()),
+                    )
+                    .collect(),
+                )),
+            )
+            .nest(2);
+    }
+
+    if let Some(from) = &select.from_clause() {
+        doc = doc.append(
+            Doc::line_or_space()
+                .append(Doc::text("from"))
+                .append(Doc::space())
+                .append(Doc::text(
+                    from.from_items().next().unwrap().syntax().to_string(),
+                )),
+        );
+    }
+
+    if let Some(group) = &select.group_by_clause() {
+        doc = doc.append(
+            Doc::line_or_space()
+                .append(Doc::text("group by"))
+                .append(Doc::space())
+                .append(Doc::text(
+                    group.group_by_list().unwrap().syntax().to_string(),
+                )),
+        );
+    }
+
+    doc.group()
+}
+
+pub fn fmt(text: &str) -> String {
+    let parse = ast::SourceFile::parse(text);
+    let file = parse.tree();
+    let doc = build_source_file(&file);
+    print(&doc, &PrintOptions::default())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use insta::assert_snapshot;
+
+    #[test]
+    fn select() {
+        assert_snapshot!(fmt("
+select a(), date_trunc(1, 2), foo(), avg(a - b), bar(carrot), buzz(potato), foo.b from t group by c;
+create table t(a int, b text);
+"), @r"
+        select 
+          a(),
+          date_trunc(1, 2),
+          foo(),
+          avg(a - b),
+          bar(carrot),
+          buzz(potato),
+          foo.b
+        from t
+        group by c;
+
+        create table t(a int, b text);
+        ");
+    }
+}