From 9fb29e99fa6d5cd04ef88786fe188562d76f029d Mon Sep 17 00:00:00 2001
From: prql-bot <107324867+prql-bot@users.noreply.github.com>
Date: Sat, 8 Aug 2026 06:49:51 +0000
Subject: [PATCH] fix: backtick parameter names in transform argument errors

---
 .../prqlc/src/semantic/resolver/transforms.rs |  8 ++--
 .../prqlc/tests/integration/error_messages.rs | 46 ++++++++++++++++++-
 2 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/prqlc/prqlc/src/semantic/resolver/transforms.rs b/prqlc/prqlc/src/semantic/resolver/transforms.rs
index 1026f3c0aca2..6860a565c8c4 100644
--- a/prqlc/prqlc/src/semantic/resolver/transforms.rs
+++ b/prqlc/prqlc/src/semantic/resolver/transforms.rs
@@ -101,7 +101,7 @@ impl Resolver<'_> {
                     let span = side.span;
                     let ident = side.clone().try_cast(
                         ExprKind::into_literal,
-                        Some("side"),
+                        Some("`side`"),
                         "inner, left, right or full",
                     )?;
 
@@ -242,7 +242,7 @@ impl Resolver<'_> {
                     let span = by.span;
                     let ident = by.clone().try_cast(
                         ExprKind::into_literal,
-                        Some("by"),
+                        Some("`by`"),
                         "position or name",
                     )?;
 
@@ -431,7 +431,7 @@ impl Resolver<'_> {
                     let span = take.span;
                     let ident = take.clone().try_cast(
                         ExprKind::into_literal,
-                        Some("take"),
+                        Some("`take`"),
                         "early or late",
                     )?;
 
@@ -526,7 +526,7 @@ impl Resolver<'_> {
                 let res = {
                     let span = format.span;
                     let format = format
-                        .try_cast(ExprKind::into_literal, Some("format"), "csv or json")?
+                        .try_cast(ExprKind::into_literal, Some("`format`"), "csv or json")?
                         .to_string();
                     match format.as_str() {
                         "\"csv\"" => from_text::parse_csv(&text)
diff --git a/prqlc/prqlc/tests/integration/error_messages.rs b/prqlc/prqlc/tests/integration/error_messages.rs
index d77fb0180a16..fb898550bbd9 100644
--- a/prqlc/prqlc/tests/integration/error_messages.rs
+++ b/prqlc/prqlc/tests/integration/error_messages.rs
@@ -562,11 +562,55 @@ fn tuple_uniq_take_wrong() {
        │
      3 │     select (tuple_uniq take:bar this)
        │                             ─┬─
-       │                              ╰─── take expected early or late, but found `this.foo.bar`
+       │                              ╰─── `take` expected early or late, but found `this.foo.bar`
     ───╯
     ");
 }
 
+/// The other three transforms that resolve a parameter to a literal report the
+/// parameter name the same way. An s-string reaches the cast without being a
+/// literal, which is the path that produces these.
+#[test]
+fn transform_param_not_a_literal() {
+    assert_snapshot!(compile(r###"
+    from x
+    join y (==id) side:s"left"
+    "###).unwrap_err(), @r#"
+    Error:
+       ╭─[ :3:24 ]
+       │
+     3 │     join y (==id) side:s"left"
+       │                        ───┬───
+       │                           ╰───── `side` expected inner, left, right or full, but found `s"left"`
+    ───╯
+    "#);
+
+    assert_snapshot!(compile(r###"
+    from foo
+    append by:s"name" baz
+    "###).unwrap_err(), @r#"
+    Error:
+       ╭─[ :3:15 ]
+       │
+     3 │     append by:s"name" baz
+       │               ───┬───
+       │                  ╰───── `by` expected position or name, but found `s"name"`
+    ───╯
+    "#);
+
+    assert_snapshot!(compile(r###"
+    from_text format:s"csv" "a,b"
+    "###).unwrap_err(), @r#"
+    Error:
+       ╭─[ :2:22 ]
+       │
+     2 │     from_text format:s"csv" "a,b"
+       │                      ───┬──
+       │                         ╰──── `format` expected csv or json, but found `s"csv"`
+    ───╯
+    "#);
+}
+
 #[test]
 fn append_by_name_wildcard() {
     assert_snapshot!(compile(r"from foo | append by:name (from bar)").unwrap_err(), @"