rescript-lang · zth · Sep 26, 2023 · Sep 20, 2023 · Sep 21, 2023 · Sep 21, 2023
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -27,6 +27,7 @@
 
 - A little performance improvement for JSX V4 runtime helper by removing one object allocation for components with key prop. https://github.com/rescript-lang/rescript-compiler/pull/6376
 - The error message for "toplevel expressions should evaluate to unit" has been revamped and improved. https://github.com/rescript-lang/rescript-compiler/pull/6407
+- Improve "Somewhere wanted" error messages by changing wording and adding more context + suggested solutions to the error messages where appropriate. https://github.com/rescript-lang/rescript-compiler/pull/6410
 
 # 11.0.0-rc.3
 

diff --git a/jscomp/build_tests/super_errors/expected/array_item_type_mismatch.res.expected b/jscomp/build_tests/super_errors/expected/array_item_type_mismatch.res.expected
@@ -0,0 +1,17 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/array_item_type_mismatch.res[0m:[2m1:16-22[0m
+
+  [1;31m1[0m [2m│[0m let x = [1, 2, [1;31m"hello"[0m]
+  2 [2m│[0m 
+
+  This array item has type: [1;31mstring[0m
+  But this array is expected to have items of type: [1;33mint[0m
+
+  Arrays can only contain items of the same type.
+
+  Possible solutions:
+  - Convert all values in the array to the same type.
+  - Use a tuple, if your array is of fixed length. Tuples can mix types freely, and compiles to a JavaScript array. Example of a tuple: `let myTuple = (10, "hello", 15.5, true)
+
+  You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/collections.res.expected b/jscomp/build_tests/super_errors/expected/collections.res.expected
@@ -7,6 +7,6 @@
   3 [2m│[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/comparison_operator.res.expected b/jscomp/build_tests/super_errors/expected/comparison_operator.res.expected
@@ -0,0 +1,13 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/comparison_operator.res[0m:[2m3:17[0m
+
+  1 [2m│[0m let f = Some(0)
+  2 [2m│[0m 
+  [1;31m3[0m [2m│[0m let x = 100 === [1;31mf[0m
+  4 [2m│[0m 
+
+  This has type: [1;31moption<int>[0m
+  But it's being compared to something of type: [1;33mint[0m
+
+  You can only compare things of the same type.
diff --git a/jscomp/build_tests/super_errors/expected/function_argument_mismatch.res.expected b/jscomp/build_tests/super_errors/expected/function_argument_mismatch.res.expected
@@ -0,0 +1,13 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/function_argument_mismatch.res[0m:[2m3:28-30[0m
+
+  1 [2m│[0m let makeName = (s, i) => s ++ i
+  2 [2m│[0m 
+  [1;31m3[0m [2m│[0m let name = makeName("123", [1;31m123[0m)
+  4 [2m│[0m 
+
+  This has type: [1;31mint[0m
+  But this function argument is expecting: [1;33mstring[0m
+
+  You can convert [1;33mint[0m to [1;33mstring[0m with [1;33mBelt.Int.toString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/function_call_mismatch.res.expected b/jscomp/build_tests/super_errors/expected/function_call_mismatch.res.expected
@@ -0,0 +1,12 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/function_call_mismatch.res[0m:[2m6:3-10[0m
+
+  4 [2m│[0m 
+  5 [2m│[0m let cloneInTemp = (temp: string): string => {
+  [1;31m6[0m [2m│[0m   [1;31mcd(temp)[0m
+  7 [2m│[0m   exec("git clone [email protected]:myorg/myrepo.git")
+  8 [2m│[0m }
+
+  This function call returns: [1;31mstring[0m
+  But it's expected to return: [1;33munit[0m
diff --git a/jscomp/build_tests/super_errors/expected/function_return_mismatch.res.expected b/jscomp/build_tests/super_errors/expected/function_return_mismatch.res.expected
@@ -0,0 +1,12 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/function_return_mismatch.res[0m:[2m9:3-5[0m
+
+   7 [2m│[0m 
+   8 [2m│[0m let x = fnExpectingCleanup(() => {
+   [1;31m9[0m [2m│[0m   [1;31m123[0m
+  10 [2m│[0m })
+  11 [2m│[0m 
+
+  This has type: [1;31mint[0m
+  But it's expected to have type: [1;33mcleanup[0m [2m(defined as[0m [1;33munit => unit[0m[2m)[0m
diff --git a/jscomp/build_tests/super_errors/expected/highlighting1.res.expected b/jscomp/build_tests/super_errors/expected/highlighting1.res.expected
@@ -8,6 +8,6 @@
   4 [2m│[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/highlighting2.res.expected b/jscomp/build_tests/super_errors/expected/highlighting2.res.expected
@@ -9,6 +9,6 @@
   5 [2m┆[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/highlighting3.res.expected b/jscomp/build_tests/super_errors/expected/highlighting3.res.expected
@@ -9,6 +9,6 @@
   5 [2m│[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/highlighting5.res.expected b/jscomp/build_tests/super_errors/expected/highlighting5.res.expected
@@ -8,6 +8,6 @@
   3 [2m│[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/if_branch_mismatch.res.expected b/jscomp/build_tests/super_errors/expected/if_branch_mismatch.res.expected
@@ -0,0 +1,16 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/if_branch_mismatch.res[0m:[2m4:3-5[0m
+
+  2 [2m│[0m   "123"
+  3 [2m│[0m } else {
+  [1;31m4[0m [2m│[0m   [1;31m123[0m
+  5 [2m│[0m }
+  6 [2m│[0m 
+
+  This has type: [1;31mint[0m
+  But this [1;33mif[0m statement is expected to return: [1;33mstring[0m
+
+  [1;33mif[0m expressions must return the same type in all branches ([1;33mif[0m, [1;33melse if[0m, [1;33melse[0m).
+
+  You can convert [1;33mint[0m to [1;33mstring[0m with [1;33mBelt.Int.toString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/if_condition_mismatch.res.expected b/jscomp/build_tests/super_errors/expected/if_condition_mismatch.res.expected
@@ -0,0 +1,12 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/if_condition_mismatch.res[0m:[2m1:12-18[0m
+
+  [1;31m1[0m [2m│[0m let x = if [1;31m"horse"[0m {
+  2 [2m│[0m   ()
+  3 [2m│[0m }
+
+  This has type: [1;31mstring[0m
+  But [1;33mif[0m conditions must always be of type: [1;33mbool[0m
+
+  To fix this, change the highlighted code so it evaluates to a [1;33mbool[0m.
diff --git a/jscomp/build_tests/super_errors/expected/math_operator_constant.res.expected b/jscomp/build_tests/super_errors/expected/math_operator_constant.res.expected
@@ -0,0 +1,20 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/math_operator_constant.res[0m:[2m3:15-17[0m
+
+  1 [2m│[0m let num = 0
+  2 [2m│[0m 
+  [1;31m3[0m [2m│[0m let x = num + [1;31m12.[0m
+  4 [2m│[0m 
+
+  This value has type: [1;31mfloat[0m
+  But it's being used with the [1;33m+[0m operator, which works on: [1;33mint[0m
+
+  Floats and ints have their own mathematical operators. This means you cannot add a float and an int without converting between the two.
+
+  Possible solutions:
+  - Ensure all values in this calculation has the type [1;33mint[0m. You can convert between floats and ints via [1;33mBelt.Float.toInt[0m and [1;33mBelt.Int.fromFloat[0m.
+  - Make [1;33m12.[0m an [1;33mint[0m by removing the dot or explicitly converting to int
+
+  You can convert [1;33mfloat[0m to [1;33mint[0m with [1;33mBelt.Float.toInt[0m.
+  If this is a literal, try a number without a trailing dot (e.g. [1;33m20[0m).
diff --git a/jscomp/build_tests/super_errors/expected/math_operator_float.res.expected b/jscomp/build_tests/super_errors/expected/math_operator_float.res.expected
@@ -0,0 +1,20 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/math_operator_float.res[0m:[2m3:9-11[0m
+
+  1 [2m│[0m let num = 0
+  2 [2m│[0m 
+  [1;31m3[0m [2m│[0m let x = [1;31mnum[0m +. 12.
+  4 [2m│[0m 
+
+  This has type: [1;31mint[0m
+  But it's being used with the [1;33m+.[0m operator, which works on: [1;33mfloat[0m
+
+  Floats and ints have their own mathematical operators. This means you cannot add a float and an int without converting between the two.
+
+  Possible solutions:
+  - Ensure all values in this calculation has the type [1;33mfloat[0m. You can convert between floats and ints via [1;33mBelt.Float.toInt[0m and [1;33mBelt.Int.fromFloat[0m.
+  - Change the operator to [1;33m+[0m, which works on [1;33mint[0m
+
+  You can convert [1;33mint[0m to [1;33mfloat[0m with [1;33mBelt.Int.toFloat[0m.
+  If this is a literal, try a number with a trailing dot (e.g. [1;33m20.[0m).
diff --git a/jscomp/build_tests/super_errors/expected/math_operator_int.res.expected b/jscomp/build_tests/super_errors/expected/math_operator_int.res.expected
@@ -0,0 +1,20 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/math_operator_int.res[0m:[2m3:9-11[0m
+
+  1 [2m│[0m let num = 0.
+  2 [2m│[0m 
+  [1;31m3[0m [2m│[0m let x = [1;31mnum[0m + 12.
+  4 [2m│[0m 
+
+  This has type: [1;31mfloat[0m
+  But it's being used with the [1;33m+[0m operator, which works on: [1;33mint[0m
+
+  Floats and ints have their own mathematical operators. This means you cannot add a float and an int without converting between the two.
+
+  Possible solutions:
+  - Ensure all values in this calculation has the type [1;33mint[0m. You can convert between floats and ints via [1;33mBelt.Float.toInt[0m and [1;33mBelt.Int.fromFloat[0m.
+  - Change the operator to [1;33m+.[0m, which works on [1;33mfloat[0m
+
+  You can convert [1;33mfloat[0m to [1;33mint[0m with [1;33mBelt.Float.toInt[0m.
+  If this is a literal, try a number without a trailing dot (e.g. [1;33m20[0m).
diff --git a/jscomp/build_tests/super_errors/expected/primitives1.res.expected b/jscomp/build_tests/super_errors/expected/primitives1.res.expected
@@ -6,8 +6,14 @@
   [1;31m2[0m [2m│[0m [1;31m2.[0m + 2
   3 [2m│[0m 
 
-  This has type: [1;31mfloat[0m
-  Somewhere wanted: [1;33mint[0m
+  This value has type: [1;31mfloat[0m
+  But it's being used with the [1;33m+[0m operator, which works on: [1;33mint[0m
+
+  Floats and ints have their own mathematical operators. This means you cannot add a float and an int without converting between the two.
+
+  Possible solutions:
+  - Ensure all values in this calculation has the type [1;33mint[0m. You can convert between floats and ints via [1;33mBelt.Float.toInt[0m and [1;33mBelt.Int.fromFloat[0m.
+  - Make [1;33m2.[0m an [1;33mint[0m by removing the dot or explicitly converting to int
 
   You can convert [1;33mfloat[0m to [1;33mint[0m with [1;33mBelt.Float.toInt[0m.
   If this is a literal, try a number without a trailing dot (e.g. [1;33m20[0m).
diff --git a/jscomp/build_tests/super_errors/expected/primitives11.res.expected b/jscomp/build_tests/super_errors/expected/primitives11.res.expected
@@ -8,7 +8,7 @@
   6 [2m│[0m 
 
   This has type: [1;31mb[0m [2m(defined as[0m [1;31moption<bb>[0m[2m)[0m
-  Somewhere wanted: [1;33ma[0m [2m(defined as[0m [1;33moption<aa>[0m[2m)[0m
+  But it's expected to have type: [1;33ma[0m [2m(defined as[0m [1;33moption<aa>[0m[2m)[0m
 
   The incompatible parts:
     [1;31mbb[0m [2m(defined as[0m [1;31moption<int>[0m[2m)[0m vs [1;33maa[0m [2m(defined as[0m [1;33moption<string>[0m[2m)[0m

diff --git a/jscomp/build_tests/super_errors/expected/primitives2.res.expected b/jscomp/build_tests/super_errors/expected/primitives2.res.expected
@@ -7,6 +7,6 @@
   3 [2m│[0m 
 
   This has type: [1;31mint[0m
-  Somewhere wanted: [1;33mstring[0m
+  But this function argument is expecting: [1;33mstring[0m
 
   You can convert [1;33mint[0m to [1;33mstring[0m with [1;33mBelt.Int.toString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/primitives6.res.expected b/jscomp/build_tests/super_errors/expected/primitives6.res.expected
@@ -8,7 +8,7 @@
   4 [2m│[0m 
 
   This has type: [1;31mint[0m
-  Somewhere wanted: [1;33mfloat[0m
+  But it's expected to have type: [1;33mfloat[0m
 
   You can convert [1;33mint[0m to [1;33mfloat[0m with [1;33mBelt.Int.toFloat[0m.
   If this is a literal, try a number with a trailing dot (e.g. [1;33m20.[0m).
diff --git a/jscomp/build_tests/super_errors/expected/primitives7.res.expected b/jscomp/build_tests/super_errors/expected/primitives7.res.expected
@@ -8,7 +8,7 @@
   4 [2m│[0m 
 
   This has type: [1;31mlist<int>[0m
-  Somewhere wanted: [1;33mlist<float>[0m
+  But this function argument is expecting: [1;33mlist<float>[0m
 
   The incompatible parts:
     [1;31mint[0m vs [1;33mfloat[0m

diff --git a/jscomp/build_tests/super_errors/expected/primitives9.res.expected b/jscomp/build_tests/super_errors/expected/primitives9.res.expected
@@ -6,6 +6,6 @@
   2 [2m│[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/record_type_spreads_deep_sub.res.expected b/jscomp/build_tests/super_errors/expected/record_type_spreads_deep_sub.res.expected
@@ -9,6 +9,6 @@
   10 [2m│[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/set_record_field_type_match.res.expected b/jscomp/build_tests/super_errors/expected/set_record_field_type_match.res.expected
@@ -0,0 +1,13 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/set_record_field_type_match.res[0m:[2m11:13-14[0m
+
+   9 [2m│[0m }
+  10 [2m│[0m 
+  [1;31m11[0m [2m│[0m user.name = [1;31m12[0m
+  12 [2m│[0m 
+
+  You're assigning something to this field that has type: [1;31mint[0m
+  But this record field is of type: [1;33mstring[0m
+
+  You can convert [1;33mint[0m to [1;33mstring[0m with [1;33mBelt.Int.toString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/switch_different_types.res.expected b/jscomp/build_tests/super_errors/expected/switch_different_types.res.expected
@@ -0,0 +1,14 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/switch_different_types.res[0m:[2m7:10-23[0m
+
+  5 [2m│[0m   switch foo {
+  6 [2m│[0m   | "world" => ()
+  [1;31m7[0m [2m│[0m   | _ => [1;31msomeFunction()[0m
+  8 [2m│[0m   }
+  9 [2m│[0m }
+
+  This has type: [1;31mstring[0m
+  But this switch is expected to return: [1;33munit[0m
+
+  All branches in a [1;33mswitch[0m must return the same type. To fix this, change your branch to return the expected type.
diff --git a/jscomp/build_tests/super_errors/expected/switch_guard.res.expected b/jscomp/build_tests/super_errors/expected/switch_guard.res.expected
@@ -0,0 +1,14 @@
+
+  [1;31mWe've found a bug for you![0m
+  [36m/.../fixtures/switch_guard.res[0m:[2m6:16-22[0m
+
+  4 [2m│[0m let bar = () => {
+  5 [2m│[0m   switch foo {
+  [1;31m6[0m [2m│[0m   | "world" if [1;31m"horse"[0m => ()
+  7 [2m│[0m   | _ => someFunction()
+  8 [2m│[0m   }
+
+  This has type: [1;31mstring[0m
+  But [1;33mif[0m conditions must always be of type: [1;33mbool[0m
+
+  To fix this, change the highlighted code so it evaluates to a [1;33mbool[0m.
diff --git a/jscomp/build_tests/super_errors/expected/syntaxErrors4.res.expected b/jscomp/build_tests/super_errors/expected/syntaxErrors4.res.expected
@@ -13,6 +13,6 @@
   23 [2m│[0m /* */
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But it's expected to have type: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/type1.res.expected b/jscomp/build_tests/super_errors/expected/type1.res.expected
@@ -5,8 +5,14 @@
   [1;31m1[0m [2m│[0m let x = [1;31m2.[0m + 2
   2 [2m│[0m 
 
-  This has type: [1;31mfloat[0m
-  Somewhere wanted: [1;33mint[0m
+  This value has type: [1;31mfloat[0m
+  But it's being used with the [1;33m+[0m operator, which works on: [1;33mint[0m
+
+  Floats and ints have their own mathematical operators. This means you cannot add a float and an int without converting between the two.
+
+  Possible solutions:
+  - Ensure all values in this calculation has the type [1;33mint[0m. You can convert between floats and ints via [1;33mBelt.Float.toInt[0m and [1;33mBelt.Int.fromFloat[0m.
+  - Make [1;33m2.[0m an [1;33mint[0m by removing the dot or explicitly converting to int
 
   You can convert [1;33mfloat[0m to [1;33mint[0m with [1;33mBelt.Float.toInt[0m.
   If this is a literal, try a number without a trailing dot (e.g. [1;33m20[0m).
diff --git a/jscomp/build_tests/super_errors/expected/type2.res.expected b/jscomp/build_tests/super_errors/expected/type2.res.expected
@@ -9,6 +9,6 @@
   8 [2m│[0m 
 
   This has type: [1;31mstring[0m
-  Somewhere wanted: [1;33mint[0m
+  But this function argument is expecting: [1;33mint[0m
 
   You can convert [1;33mstring[0m to [1;33mint[0m with [1;33mBelt.Int.fromString[0m.
diff --git a/jscomp/build_tests/super_errors/expected/unicode_location.res.expected b/jscomp/build_tests/super_errors/expected/unicode_location.res.expected
@@ -7,6 +7,6 @@
     [2m│[0m (unicode symbols of length 2)
 
   This has type: [1;31mint[0m
-  Somewhere wanted: [1;33mstring[0m
+  But this function argument is expecting: [1;33mstring[0m
 
   You can convert [1;33mint[0m to [1;33mstring[0m with [1;33mBelt.Int.toString[0m.