Enforce stricter rules on reference access (#1718)

This changes the following: 1. If given a union type, the member must exist on each member of that type 2. If accessing a member off `Reference<D, Null>`, give a `Reference<D, Null>` Also: * Improve error messages thrown during member access. * Add test around accessing members off of a function type
2026-09-13 21:31:52 +02:00 · 2026-07-06 19:24:14 -07:00
parent 3fc97d8dad
commit 2ec62c99a7
28 changed files with 339 additions and 70 deletions
@@ -36,6 +36,7 @@ class AProperties {
  someListing: Listing<Int>
  someList: List<Int>
  nonInt: String
+  nullProp: Null
 }

 class B extends Resource {
@@ -64,6 +65,7 @@ class K {
  bId: String | *Ref<String>?
  aProperties: AProperties | *Ref<AProperties>?
  bProperties: BProperties | *Ref<BProperties>?
+  nullProp: Ref<Null>?
  aValues: Listing<Int | Ref<Int?>>?
  bValues: Listing<String | Ref<String?>>?
  splitUnion: Ref<Listing<String> | Listing<Int>>?
@@ -91,6 +93,7 @@ k: K = new {
  bId = bRef.id
  aProperties = aRef.outputs
  bProperties = bRef.outputs
+  nullProp = aRef.outputs.nullProp.prop1.prop2["foo"].prop3
  aValues {
    aRef.outputs.foo
    aRef.outputs.someMapping["key"]
@@ -17,39 +17,40 @@ local class Holder {
  optional: Mapping<String, Int?>
  listing: Listing<Int>
  union: Listing<String> | Listing<Int>
+  constrainedType: String(isEmpty)
 }

-local const h: Holder = new {
-  num = 1
-  text = "t"
-  lit = "literal"
-  small = 8
-  optional { ["k"] = 5 }
-  listing { 1; 2 }
-  union = new Listing<Int> { 1 }
+local class OtherHolder {
+  num: Int?
+  constrainedType: String(isEmpty)
 }

-local hRef1: Ref<Holder> = ref.Reference(d, Holder, h)
-local hRef2: Ref<Holder> = ref.Reference(d, Holder, h)
+local holderRef: Ref<Holder> = ref.Reference(d, Holder, null)
+local holderRef2: Ref<Holder> = ref.Reference(d, Holder, null)
+local otherHolderRef: Ref<OtherHolder> = ref.Reference(d, OtherHolder, null)

 facts {
  ["equality"] {
-    hRef1 == hRef2
-    hRef1.num == hRef2.num
-    hRef1.lit == hRef2.lit
-    hRef1.small == hRef2.small
-    hRef1.optional["k"] == hRef2.optional["k"]
-    hRef1.listing[0] == hRef2.listing[0]
-    hRef1.union == hRef2.union
+    holderRef == holderRef2
+    holderRef.num == holderRef2.num
+    holderRef.lit == holderRef2.lit
+    holderRef.small == holderRef2.small
+    holderRef.optional["k"] == holderRef2.optional["k"]
+    holderRef.listing[0] == holderRef2.listing[0]
+    holderRef.union == holderRef2.union
+  }
+
+  ["equality -- constraint gets erased"] {
+    holderRef.constrainedType == otherHolderRef.constrainedType
  }

  ["inequality"] {
-    hRef1.num != hRef2.text
+    holderRef.num != holderRef2.text
  }

  ["set deduplication"] {
-    Set(hRef1.num, hRef2.num).length == 1
-    Set(hRef1.union, hRef2.union).length == 1
-    Set(hRef1.num, hRef2.text).length == 2
+    Set(holderRef.num, holderRef2.num).length == 1
+    Set(holderRef.union, holderRef2.union).length == 1
+    Set(holderRef.num, holderRef2.text).length == 2
  }
 }
@@ -6,7 +6,7 @@ class D extends ref.Domain {
 typealias Ref<T> = ref.Reference<D, T>
 local d: D = new {}

-test = ref.Reference(d, String, "") as Ref<Alias1?>
+test = ref.Reference(d, String, "") as Ref<Alias1>

-typealias Alias1 = Int | Alias2?
+typealias Alias1 = Int | Alias2
 typealias Alias2 = String(length < 5)
@@ -0,0 +1,17 @@
+import "pkl:ref"
+
+class D extends ref.Domain {
+  function renderReference(_): String = throw("not implemented")
+}
+
+class Bird {
+  name: String
+}
+
+class Holder {
+  $: Bird | Int
+}
+
+myRef: ref.Reference<D, Bird | Int> = ref.Reference(new D {}, Holder, null).$
+
+res = myRef.name
@@ -0,0 +1,13 @@
+import "pkl:ref"
+
+class D extends ref.Domain {
+  function renderReference(_): String = throw("not implemented")
+}
+
+class Holder {
+  $: Duration | Listing<String>
+}
+
+local myRef = ref.Reference(new D {}, Holder, null).$
+
+res = myRef[0]
@@ -0,0 +1,9 @@
+import "pkl:ref"
+
+class D extends ref.Domain {
+  function renderReference(_): String = throw("not implemented")
+}
+
+local myRef = ref.Reference(new D {}, Listing, null)
+
+res = myRef.name
@@ -0,0 +1,13 @@
+import "pkl:ref"
+
+class D extends ref.Domain {
+  function renderReference(_): String = throw("not implemented")
+}
+
+class Holder {
+  func: (Int) -> Boolean
+}
+
+local myRef = ref.Reference(new D {}, Holder, null).func
+
+res = myRef.name
@@ -6,7 +6,7 @@ class D extends ref.Domain {
 local d: D = new {}
 typealias Ref<T> = ref.Reference<D, T>

-test = ref.Reference(d, String, "") as Ref<Alias1?>
+test = ref.Reference(d, String, "") as Ref<Alias1>

-typealias Alias1 = Int | Alias2?
+typealias Alias1 = Int | Alias2
 typealias Alias2 = Boolean
@@ -20,6 +20,7 @@ k {
  bId = "${b.id}"
  aProperties = "${a.outputs}"
  bProperties = "${b.outputs}"
+  nullProp = "${a.outputs.nullProp.prop1.prop2[foo].prop3}"
  aValues {
    "${a.outputs.foo}"
    "${a.outputs.someMapping[key]}"
@@ -43,12 +44,13 @@ j {
  bId = null
  aProperties = "${a.outputs}"
  bProperties = null
+  nullProp = null
  aValues = null
  bValues = null
  splitUnion = "${a.outputs.someListing}"
 }
 refInterpolation = "${a.outputs.someListing[1]}"
-kInterpolation = "new K { aId = Reference(new D {}, String, new A { name = \"a\"; id = \"some-a-value\" }).id; bId = Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).id; aProperties = Reference(new D {}, reference#AProperties, new A { name = \"a\"; id = \"some-a-value\" }).outputs; bProperties = Reference(new D {}, reference#BProperties, new B { name = \"b\"; id = \"some-b-value\" }).outputs; aValues { Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.foo; Reference(new D {}, Int | Null, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someMapping[\"key\"]; Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someMap[new MapKey { k = 123 }]; Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someListing[0]; Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someList[9223372036854775807]; Reference(new D {}, Int, new B { name = \"b\"; id = \"some-b-value\" }).outputs.nonString }; bValues { Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.foo; Reference(new D {}, Null | String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someMapping[\"key\"]; Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someMap[new MapKey { k = 123 }]; Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someListing[0]; Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someList[9223372036854775807]; Reference(new D {}, String, new A { name = \"a\"; id = \"some-a-value\" }).outputs.nonInt }; splitUnion = null }"
+kInterpolation = "new K { aId = Reference(new D {}, String, new A { name = \"a\"; id = \"some-a-value\" }).id; bId = Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).id; aProperties = Reference(new D {}, reference#AProperties, new A { name = \"a\"; id = \"some-a-value\" }).outputs; bProperties = Reference(new D {}, reference#BProperties, new B { name = \"b\"; id = \"some-b-value\" }).outputs; nullProp = Reference(new D {}, Null, new A { name = \"a\"; id = \"some-a-value\" }).outputs.nullProp.prop1.prop2[\"foo\"].prop3; aValues { Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.foo; Reference(new D {}, Int | Null, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someMapping[\"key\"]; Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someMap[new MapKey { k = 123 }]; Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someListing[0]; Reference(new D {}, Int, new A { name = \"a\"; id = \"some-a-value\" }).outputs.someList[9223372036854775807]; Reference(new D {}, Int, new B { name = \"b\"; id = \"some-b-value\" }).outputs.nonString }; bValues { Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.foo; Reference(new D {}, Null | String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someMapping[\"key\"]; Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someMap[new MapKey { k = 123 }]; Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someListing[0]; Reference(new D {}, String, new B { name = \"b\"; id = \"some-b-value\" }).outputs.someList[9223372036854775807]; Reference(new D {}, String, new A { name = \"a\"; id = \"some-a-value\" }).outputs.nonInt }; splitUnion = null }"
 aValuesJoined = """
  ${a.outputs.foo}
  ${a.outputs.someMapping[key]}
@@ -8,6 +8,9 @@ facts {
    true
    true
  }
+  ["equality -- constraint gets erased"] {
+    true
+  }
  ["inequality"] {
    true
  }
@@ -5,7 +5,7 @@ xx | typealias Alias2 = String(length < 5)
                        ^^^^^^^^^^^^^^^^^^
 at reference11#Alias2 (file:///$snippetsDir/input/errors/reference11.pkl)

-xx | typealias Alias1 = Int | Alias2?
+xx | typealias Alias1 = Int | Alias2
                              ^^^^^^
 at reference11#Alias1 (file:///$snippetsDir/input/errors/reference11.pkl)

@@ -13,8 +13,8 @@ x | typealias Ref<T> = ref.Reference<D, T>
                       ^^^^^^^^^^^^^^^^^^^
 at reference11#Ref (file:///$snippetsDir/input/errors/reference11.pkl)

-x | test = ref.Reference(d, String, "") as Ref<Alias1?>
-                                           ^^^^^^^^^^^^
+x | test = ref.Reference(d, String, "") as Ref<Alias1>
+                                           ^^^^^^^^^^^
 at reference11#test (file:///$snippetsDir/input/errors/reference11.pkl)

 xxx | renderer.renderDocument(value)
@@ -5,6 +5,8 @@ x | test = ref.Reference(d, Mapping, "").default
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference13#test (file:///$snippetsDir/input/errors/reference13.pkl)

+Cannot reference property `default` in class `Mapping`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)
@@ -5,6 +5,8 @@ x | test = ref.Reference(d, Listing, "").default
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference14#test (file:///$snippetsDir/input/errors/reference14.pkl)

+Cannot reference property `default` in class `Listing`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)
@@ -5,6 +5,8 @@ x | test = ref.Reference(d, Dynamic, "").default
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference15#test (file:///$snippetsDir/input/errors/reference15.pkl)

+Cannot reference property `default` in class `Dynamic`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)
@@ -5,6 +5,8 @@ xx | test = ref.Reference(d, ReferencedModule.getClass(), "").output
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference16#test (file:///$snippetsDir/input/errors/reference16.pkl)

+Cannot reference property `output` because it is defined inside external class `Module`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)
@@ -5,6 +5,8 @@ xx | test = ref.Reference(d, ReferencedModuleWithOutputOverride.getClass(), "").
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference17#test (file:///$snippetsDir/input/errors/reference17.pkl)

+Cannot reference property `output` because it is defined inside external class `Module`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)
@@ -5,6 +5,8 @@ xx | test = ref.Reference(d, ModuleSubclass, "").output
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference18#test (file:///$snippetsDir/input/errors/reference18.pkl)

+Cannot reference property `output` because it is defined inside external class `Module`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)
@@ -0,0 +1,17 @@
+–– Pkl Error ––
+Cannot find property `name` in object of type `pkl.ref#Reference<reference24#D, Int | reference24#Bird>`.
+
+xx | res = myRef.name
+           ^^^^^^^^^^
+at reference24#res (file:///$snippetsDir/input/errors/reference24.pkl)
+
+Cannot find property `name` in type `Int | reference24#Bird`.
+	└─ Cannot find property `name` in type `Int`.
+
+xxx | renderer.renderDocument(value)
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)
+
+xxx | if (renderer is BytesRenderer) renderer.renderDocument(value) else text.encodeToBytes("UTF-8")
+                                                                         ^^^^
+at pkl.base#Module.output.bytes (pkl:base)
@@ -0,0 +1,19 @@
+–– Pkl Error ––
+Operator `[]` is not defined for operand types `pkl.ref#Reference<reference25#D, Duration | Listing<String>>` and `Int`.
+Left operand : Reference(new D {}, Duration | Listing<String>, null).$
+Right operand: 0
+
+xx | res = myRef[0]
+           ^^^^^^^^
+at reference25#res (file:///$snippetsDir/input/errors/reference25.pkl)
+
+Operator `[]` is not defined for operand types `Duration | Listing<String>` and `Int`.
+	└─ Operator `[]` is not defined for operand types `Duration` and `Int`.
+
+xxx | renderer.renderDocument(value)
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)
+
+xxx | if (renderer is BytesRenderer) renderer.renderDocument(value) else text.encodeToBytes("UTF-8")
+                                                                         ^^^^
+at pkl.base#Module.output.bytes (pkl:base)
@@ -0,0 +1,16 @@
+–– Pkl Error ––
+Cannot find property `name` in object of type `pkl.ref#Reference<reference26#D, Listing<unknown>>`.
+
+x | res = myRef.name
+          ^^^^^^^^^^
+at reference26#res (file:///$snippetsDir/input/errors/reference26.pkl)
+
+Cannot find property `name` in type `Listing<unknown>`.
+
+xxx | renderer.renderDocument(value)
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)
+
+xxx | if (renderer is BytesRenderer) renderer.renderDocument(value) else text.encodeToBytes("UTF-8")
+                                                                         ^^^^
+at pkl.base#Module.output.bytes (pkl:base)
@@ -0,0 +1,16 @@
+–– Pkl Error ––
+Cannot find property `name` in object of type `pkl.ref#Reference<reference27#D, (Int) -> Boolean>`.
+
+xx | res = myRef.name
+           ^^^^^^^^^^
+at reference27#res (file:///$snippetsDir/input/errors/reference27.pkl)
+
+Cannot find property `name` in type `(Int) -> Boolean`.
+
+xxx | renderer.renderDocument(value)
+      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+at pkl.base#Module.output.text (pkl:base)
+
+xxx | if (renderer is BytesRenderer) renderer.renderDocument(value) else text.encodeToBytes("UTF-8")
+                                                                         ^^^^
+at pkl.base#Module.output.bytes (pkl:base)
@@ -1,5 +1,5 @@
 –– Pkl Error ––
-Expected value of type `pkl.ref#Reference<reference4#D, reference4#Alias1?>`, but got type `pkl.ref#Reference<reference4#D, String>`.
+Expected value of type `pkl.ref#Reference<reference4#D, reference4#Alias1>`, but got type `pkl.ref#Reference<reference4#D, String>`.
 Value: Reference(new D {}, String, "")

 x | typealias Ref<T> = ref.Reference<D, T>
@@ -5,6 +5,8 @@ xx | test = ref.Reference(d, String, new A {}).c
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference6#test (file:///$snippetsDir/input/errors/reference6.pkl)

+Cannot find property `c` in type `String`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)
@@ -7,6 +7,8 @@ x | test = ref.Reference(d, List, List())["hi"]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at reference7#test (file:///$snippetsDir/input/errors/reference7.pkl)

+Operator `[]` is not defined for operand types `List<unknown>` and `String`.
+
 xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 at pkl.base#Module.output.text (pkl:base)