From ea2357670a6cb2a41c6704dba06b2eb967fbe979 Mon Sep 17 00:00:00 2001
From: Maksim Volkau <max.volkov@gmail.com>
Date: Tue, 14 May 2024 21:13:38 +0200
Subject: [PATCH] feat: better error msg

---
 crates/compiler/load/tests/test_reporting.rs | 24 +++++++++++++++-----
 crates/repl_test/src/tests.rs                |  8 +++++--
 crates/reporting/src/error/type.rs           |  4 ++++
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/crates/compiler/load/tests/test_reporting.rs b/crates/compiler/load/tests/test_reporting.rs
index bbda53a5217..7fa724d357d 100644
--- a/crates/compiler/load/tests/test_reporting.rs
+++ b/crates/compiler/load/tests/test_reporting.rs
@@ -1665,7 +1665,7 @@ mod test_reporting {
             f 1
             "
         ),
-        @r"
+        @r#"
     ── TOO FEW ARGS in /code/proj/Main.roc ─────────────────────────────────────────
 
     The `f` function expects 2 arguments, but it got only 1:
@@ -1675,7 +1675,11 @@ mod test_reporting {
 
     Roc does not allow functions to be partially applied. Use a closure to
     make partial application explicit.
-    "
+
+    For example: ["a", "b"] |> \list -> Str.joinWith list ", "
+
+    or simplier: ["a", "b"] |> Str.joinWith ", "
+    "#
     );
 
     test_report!(
@@ -14214,7 +14218,7 @@ In roc, functions are always written as a lambda, like{}
             2 |> (Num.sub 3)
             "
         ),
-        @r"
+        @r#"
     ── TOO FEW ARGS in /code/proj/Main.roc ─────────────────────────────────────────
 
     The `sub` function expects 2 arguments, but it got only 1:
@@ -14224,7 +14228,11 @@ In roc, functions are always written as a lambda, like{}
 
     Roc does not allow functions to be partially applied. Use a closure to
     make partial application explicit.
-    "
+
+    For example: ["a", "b"] |> \list -> Str.joinWith list ", "
+
+    or simplier: ["a", "b"] |> Str.joinWith ", "
+    "#
     );
 
     test_report!(
@@ -14234,7 +14242,7 @@ In roc, functions are always written as a lambda, like{}
             2 |> (Num.sub 3) |> Num.sub 3
             "
         ),
-        @r"
+        @r#"
     ── TOO FEW ARGS in /code/proj/Main.roc ─────────────────────────────────────────
 
     The `sub` function expects 2 arguments, but it got only 1:
@@ -14244,6 +14252,10 @@ In roc, functions are always written as a lambda, like{}
 
     Roc does not allow functions to be partially applied. Use a closure to
     make partial application explicit.
-    "
+
+    For example: ["a", "b"] |> \list -> Str.joinWith list ", "
+
+    or simplier: ["a", "b"] |> Str.joinWith ", "
+    "#
     );
 }
diff --git a/crates/repl_test/src/tests.rs b/crates/repl_test/src/tests.rs
index 7099e22f19d..ed43a993181 100644
--- a/crates/repl_test/src/tests.rs
+++ b/crates/repl_test/src/tests.rs
@@ -642,7 +642,7 @@ fn too_few_args() {
     expect_failure(
         "Num.add 2",
         indoc!(
-            r"
+            r#"
                 ── TOO FEW ARGS ────────────────────────────────────────────────────────────────
 
                 The add function expects 2 arguments, but it got only 1:
@@ -652,7 +652,11 @@ fn too_few_args() {
 
                 Roc does not allow functions to be partially applied. Use a closure to
                 make partial application explicit.
-                "
+
+                For example: ["a", "b"] |> \list -> Str.joinWith list ", "
+
+                or simplier: ["a", "b"] |> Str.joinWith ", "
+                "#
         ),
     );
 }
diff --git a/crates/reporting/src/error/type.rs b/crates/reporting/src/error/type.rs
index e8313466217..8e839e0ef11 100644
--- a/crates/reporting/src/error/type.rs
+++ b/crates/reporting/src/error/type.rs
@@ -1237,6 +1237,10 @@ fn to_expr_report<'b>(
                                 "Roc does not allow functions to be partially applied. \
                                 Use a closure to make partial application explicit.",
                             ),
+                            alloc.reflow(
+                                r#"For example: ["a", "b"] |> \list -> Str.joinWith list ", ""#,
+                            ),
+                            alloc.reflow(r#"or simplier: ["a", "b"] |> Str.joinWith ", ""#),
                         ];
 
                         Report {