From 544c46e0e469166eb31dd54f06b5d2048d74c2ad Mon Sep 17 00:00:00 2001
From: mike <98623181+1Kinoti@users.noreply.github.com>
Date: Thu, 6 Jul 2023 11:25:39 +0300
Subject: [PATCH] improve subtyping (#9614)

# Description

the current subtyping rule needs you to define the record entries in the
same order as declared in the annotation. this pr improves that

now
```nushell
{ name: 'Him', age: 12 }

# ,

{ age: 100, name: 'It' }

# and

{ name: 'Red', age: 69, height: "5-8" }

# will all match

record<name: string, age: int>

# previously only the first one would match
```

however, something like

```nushell
{ name: 'Her' } # will not


# and

{ name: 'Car', wheels: 5 }
```

EDIT: applied JT's suggestion
---
 crates/nu-parser/src/type_check.rs | 14 ++++++++------
 crates/nu-protocol/src/ty.rs       | 12 ++++++++----
 src/tests/test_type_check.rs       | 27 +++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 10 deletions(-)

diff --git a/crates/nu-parser/src/type_check.rs b/crates/nu-parser/src/type_check.rs
index aa5ffce1b3..bef8748510 100644
--- a/crates/nu-parser/src/type_check.rs
+++ b/crates/nu-parser/src/type_check.rs
@@ -7,16 +7,18 @@ use nu_protocol::{
 pub fn type_compatible(lhs: &Type, rhs: &Type) -> bool {
     // Structural subtyping
     let is_compatible = |expected: &[(String, Type)], found: &[(String, Type)]| {
-        // the expected type is `any`
         if expected.is_empty() {
             true
-        } else if expected.len() != found.len() {
+        } else if expected.len() > found.len() {
             false
         } else {
-            expected
-                .iter()
-                .zip(found.iter())
-                .all(|(lhs, rhs)| lhs.0 == rhs.0 && type_compatible(&lhs.1, &rhs.1))
+            expected.iter().all(|(col_x, ty_x)| {
+                if let Some((_, ty_y)) = found.iter().find(|(col_y, _)| col_x == col_y) {
+                    type_compatible(ty_x, ty_y)
+                } else {
+                    false
+                }
+            })
         }
     };
 
diff --git a/crates/nu-protocol/src/ty.rs b/crates/nu-protocol/src/ty.rs
index ba4f258543..88924b505c 100644
--- a/crates/nu-protocol/src/ty.rs
+++ b/crates/nu-protocol/src/ty.rs
@@ -41,12 +41,16 @@ impl Type {
         let is_subtype_collection = |this: &[(String, Type)], that: &[(String, Type)]| {
             if this.is_empty() || that.is_empty() {
                 true
-            } else if this.len() != that.len() {
+            } else if this.len() > that.len() {
                 false
             } else {
-                this.iter()
-                    .zip(that.iter())
-                    .all(|(lhs, rhs)| lhs.0 == rhs.0 && lhs.1.is_subtype(&rhs.1))
+                this.iter().all(|(col_x, ty_x)| {
+                    if let Some((_, ty_y)) = that.iter().find(|(col_y, _)| col_x == col_y) {
+                        ty_x.is_subtype(ty_y)
+                    } else {
+                        false
+                    }
+                })
             }
         };
 
diff --git a/src/tests/test_type_check.rs b/src/tests/test_type_check.rs
index 17c9f879b1..62194bf146 100644
--- a/src/tests/test_type_check.rs
+++ b/src/tests/test_type_check.rs
@@ -59,3 +59,30 @@ fn block_not_first_class_let() -> TestResult {
         "Blocks are not support as first-class values",
     )
 }
+
+#[test]
+fn record_subtyping() -> TestResult {
+    run_test(
+        "def test [rec: record<name: string, age: int>] { $rec | describe };
+        test { age: 4, name: 'John' }",
+        "record<age: int, name: string>",
+    )
+}
+
+#[test]
+fn record_subtyping_2() -> TestResult {
+    run_test(
+        "def test [rec: record<name: string, age: int>] { $rec | describe };
+        test { age: 4, name: 'John', height: '5-9' }",
+        "record<age: int, name: string, height: string>",
+    )
+}
+
+#[test]
+fn record_subtyping_3() -> TestResult {
+    fail_test(
+        "def test [rec: record<name: string, age: int>] { $rec | describe };
+        test { name: 'Nu' }",
+        "expected",
+    )
+}