Require block params (#4505)

* Require block params

* Improve errors

src/tests/test_engine.rs

@@ -86,7 +86,7 @@ fn scope_variable() -> TestResult {
 #[test]
 fn earlier_errors() -> TestResult {
     fail_test(
-        r#"[1, "bob"] | each { $it + 3 } | each { $it / $it } | table"#,
+        r#"[1, "bob"] | each { |it| $it + 3 } | each { |it| $it / $it } | table"#,
         "int",
     )
 }

src/tests/test_iteration.rs

@@ -3,7 +3,7 @@ use crate::tests::{run_test, TestResult};
 #[test]
 fn better_block_types() -> TestResult {
     run_test(
-        r#"([1, 2, 3] | each -n { $"($it.index) is ($it.item)" }).1"#,
+        r#"([1, 2, 3] | each -n { |it| $"($it.index) is ($it.item)" }).1"#,
         "1 is 2",
     )
 }
@@ -11,14 +11,14 @@ fn better_block_types() -> TestResult {
 #[test]
 fn row_iteration() -> TestResult {
     run_test(
-        "[[name, size]; [tj, 100], [rl, 200]] | each { $it.size * 8 } | get 1",
+        "[[name, size]; [tj, 100], [rl, 200]] | each { |it| $it.size * 8 } | get 1",
         "1600",
     )
 }
 
 #[test]
 fn record_iteration() -> TestResult {
-    run_test("([[name, level]; [aa, 100], [bb, 200]] | each { $it | each { |x| if $x.column == \"level\" { $x.value + 100 } else { $x.value } } }).level | get 1", "300")
+    run_test("([[name, level]; [aa, 100], [bb, 200]] | each { |it| $it | each { |x| if $x.column == \"level\" { $x.value + 100 } else { $x.value } } }).level | get 1", "300")
 }
 
 #[test]
@@ -45,7 +45,7 @@ fn for_loops() -> TestResult {
 #[test]
 fn par_each() -> TestResult {
     run_test(
-        r#"1..10 | par-each --numbered { ([[index, item]; [$it.index, ($it.item > 5)]]).0 } | where index == 4 | get item.0"#,
+        r#"1..10 | par-each --numbered { |it| ([[index, item]; [$it.index, ($it.item > 5)]]).0 } | where index == 4 | get item.0"#,
         "false",
     )
 }

src/tests/test_parser.rs

@@ -40,7 +40,7 @@ fn alias_recursion() -> TestResult {
 
 #[test]
 fn block_param1() -> TestResult {
-    run_test("[3] | each { $it + 10 } | get 0", "13")
+    run_test("[3] | each { |it| $it + 10 } | get 0", "13")
 }
 
 #[test]
@@ -50,7 +50,7 @@ fn block_param2() -> TestResult {
 
 #[test]
 fn block_param3_list_iteration() -> TestResult {
-    run_test("[1,2,3] | each { $it + 10 } | get 1", "12")
+    run_test("[1,2,3] | each { |it| $it + 10 } | get 1", "12")
 }
 
 #[test]
@@ -70,7 +70,7 @@ fn range_iteration2() -> TestResult {
 
 #[test]
 fn simple_value_iteration() -> TestResult {
-    run_test("4 | each { $it + 10 }", "14")
+    run_test("4 | each { |it| $it + 10 }", "14")
 }
 
 #[test]
@@ -116,7 +116,7 @@ fn bad_var_name() -> TestResult {
 #[test]
 fn long_flag() -> TestResult {
     run_test(
-        r#"([a, b, c] | each --numbered { if $it.index == 1 { 100 } else { 0 } }).1"#,
+        r#"([a, b, c] | each --numbered { |it| if $it.index == 1 { 100 } else { 0 } }).1"#,
         "100",
     )
 }
@@ -314,3 +314,18 @@ fn capture_row_condition() -> TestResult {
 fn proper_missing_param() -> TestResult {
     fail_test(r#"def foo [x y z w] { }; foo a b c"#, "missing w")
 }
+
+#[test]
+fn block_arity_check1() -> TestResult {
+    fail_test(r#"ls | each { 1 }"#, "expected 1 block parameter")
+}
+
+#[test]
+fn block_arity_check2() -> TestResult {
+    fail_test(r#"ls | reduce { 1 }"#, "expected 2 block parameters")
+}
+
+#[test]
+fn block_arity_check3() -> TestResult {
+    fail_test(r#"ls | each { |x, y| 1}"#, "expected 1 block parameter")
+}

src/tests/test_strings.rs

@@ -7,13 +7,13 @@ fn build_string1() -> TestResult {
 
 #[test]
 fn build_string2() -> TestResult {
-    run_test("'nu' | each {build-string $it 'shell'}", "nushell")
+    run_test("'nu' | each { |it| build-string $it 'shell'}", "nushell")
 }
 
 #[test]
 fn build_string3() -> TestResult {
     run_test(
-        "build-string 'nu' 'shell' | each {build-string $it ' rocks'}",
+        "build-string 'nu' 'shell' | each { |it| build-string $it ' rocks'}",
         "nushell rocks",
     )
 }
@@ -21,7 +21,7 @@ fn build_string3() -> TestResult {
 #[test]
 fn build_string4() -> TestResult {
     run_test(
-        "['sam','rick','pete'] | each { build-string $it ' is studying'} | get 2",
+        "['sam','rick','pete'] | each { |it| build-string $it ' is studying'} | get 2",
         "pete is studying",
     )
 }