fix: Don't panic on invalid take (PRQL#1338)

prql-compiler/src/semantic/transforms.rs

@@ -76,7 +76,14 @@ pub fn cast_transform(resolver: &mut Resolver, closure: Closure) -> Result<Resul
             let range = match expr.kind {
                 ExprKind::Literal(Literal::Integer(n)) => Range::from_ints(None, Some(n)),
                 ExprKind::Range(range) => range,
-                _ => unimplemented!("`take` range: {expr}"),
+                _ => bail!(Error::new(Reason::Expected {
+                    who: Some("`take`".to_string()),
+                    expected: "int or range".to_string(),
+                    found: expr.to_string(),
+                })
+                // Possibly this should refer to the item after the `take` where
+                // one exists?
+                .with_span(expr.span)),
             };
 
             (TransformKind::Take { range }, tbl)

prql-compiler/src/test.rs

@@ -1797,25 +1797,6 @@ fn test_casting() {
     );
 }
 
-#[test]
-/// Start testing some error messages. This can hopefully be expanded significantly.
-fn test_errors() {
-    assert_display_snapshot!(compile(r###"
-    from x
-    select a
-    select b
-    "###).unwrap_err(),
-        @r###"
-    Error:
-    ╭─[:4:12]
-    │
-    4 │     select b
-    ·            ┬
-    ·            ╰── Unknown name b
-    ───╯
-    "###);
-}
-
 #[test]
 fn test_toposort() {
     // #1183
@@ -2351,3 +2332,37 @@ fn test_closures_and_pipelines() {
     "###
     );
 }
+
+#[test]
+/// Start testing some error messages. This can hopefully be expanded significantly.
+// It's also fine to put errors by the things that they're testing.
+fn test_errors() {
+    assert_display_snapshot!(compile(r###"
+    from x
+    select a
+    select b
+    "###).unwrap_err(),
+        @r###"
+    Error:
+    ╭─[:4:12]
+    │
+    4 │     select b
+    ·            ┬
+    ·            ╰── Unknown name b
+    ───╯
+    "###);
+
+    assert_display_snapshot!(compile(r###"
+    from employees
+    take 1.8
+    "###).unwrap_err(),
+        @r###"
+    Error:
+    ╭─[:3:10]
+    │
+    3 │     take 1.8
+    ·          ─┬─
+    ·           ╰─── `take` expected int or range, but found 1.8
+    ───╯
+    "###);
+}