generic tests

Author: CapsAdmin

test/tests/nattlua/analyzer/generic_metatable_methods.lua

@@ -0,0 +1,178 @@
+-- Bug #4: Method calls on values returned from generic constructors
+-- "type symbol : nil cannot be called"
+--
+-- When a generic function returns an object with a metatable,
+-- calling methods on the result produces "nil cannot be called".
+-- ============================================================
+-- BASELINE: metatable methods work on non-generic constructor
+-- ============================================================
+analyze[[
+    local Foo = {}
+    Foo.__index = Foo
+    type Foo.@Name = "Foo"
+    type Foo.@SelfArgument = {
+        ["value"] = number,
+        @MetaTable = Foo,
+    }
+
+    function Foo:GetValue(): number
+        return self.value
+    end
+
+    local function new_foo(): Foo.@SelfArgument
+        return setmetatable({value = 42} as Foo.@SelfArgument, Foo)
+    end
+
+    local f = new_foo()
+    local v = f:GetValue()
+    attest.equal(v, _ as number)
+]]
+-- ============================================================
+-- Test A: generic constructor, method call on local variable
+-- ============================================================
+analyze[[
+    local Foo = {}
+    Foo.__index = Foo
+    type Foo.@Name = "Foo"
+    type Foo.@SelfArgument = {
+        ["value"] = number,
+        @MetaTable = Foo,
+    }
+
+    function Foo:GetValue(): number
+        return self.value
+    end
+
+    local function new_foo<|T: any|>(): Foo.@SelfArgument
+        return setmetatable({value = 42} as Foo.@SelfArgument, Foo)
+    end
+
+    local f = new_foo<|string|>()
+    local v = f:GetValue()
+    attest.equal(v, _ as number)
+]]
+-- ============================================================
+-- Test B: generic constructor, method call without explicit type args
+-- ============================================================
+analyze[[
+    local Foo = {}
+    Foo.__index = Foo
+    type Foo.@Name = "Foo"
+    type Foo.@SelfArgument = {
+        ["value"] = number,
+        @MetaTable = Foo,
+    }
+
+    function Foo:GetValue(): number
+        return self.value
+    end
+
+    local function new_foo<|T: any|>(): Foo.@SelfArgument
+        return setmetatable({value = 42} as Foo.@SelfArgument, Foo)
+    end
+
+    local f = new_foo()
+    local v = f:GetValue()
+    attest.equal(v, _ as number)
+]]
+-- ============================================================
+-- Test C: generic constructor, inline method call (no local)
+-- ============================================================
+analyze[[
+    local Foo = {}
+    Foo.__index = Foo
+    type Foo.@Name = "Foo"
+    type Foo.@SelfArgument = {
+        ["value"] = number,
+        @MetaTable = Foo,
+    }
+
+    function Foo:GetValue(): number
+        return self.value
+    end
+
+    local function new_foo<|T: any|>(): Foo.@SelfArgument
+        return setmetatable({value = 42} as Foo.@SelfArgument, Foo)
+    end
+
+    local v = new_foo<|string|>():GetValue()
+    attest.equal(v, _ as number)
+]]
+-- ============================================================
+-- Test D: non-generic constructor, inline method call
+-- ============================================================
+analyze[[
+    local Foo = {}
+    Foo.__index = Foo
+    type Foo.@Name = "Foo"
+    type Foo.@SelfArgument = {
+        ["value"] = number,
+        @MetaTable = Foo,
+    }
+
+    function Foo:GetValue(): number
+        return self.value
+    end
+
+    local function new_foo(): Foo.@SelfArgument
+        return setmetatable({value = 42} as Foo.@SelfArgument, Foo)
+    end
+
+    local v = new_foo():GetValue()
+    attest.equal(v, _ as number)
+]]
+-- ============================================================
+-- Test E: generic constructor using typed local instead of as-cast
+-- (the pattern from our reactive project)
+-- ============================================================
+analyze[[
+    local Foo = {}
+    Foo.__index = Foo
+    type Foo.@Name = "Foo"
+    type Foo.@SelfArgument = {
+        ["value"] = number,
+        @MetaTable = Foo,
+    }
+
+    function Foo:GetValue(): number
+        return self.value
+    end
+
+    local function new_foo<|T: any|>(): Foo.@SelfArgument
+        local self: Foo.@SelfArgument = {
+            value = 42,
+        }
+        setmetatable(self, Foo)
+        return self
+    end
+
+    local f = new_foo<|string|>()
+    local v = f:GetValue()
+    attest.equal(v, _ as number)
+]]
+-- ============================================================
+-- Test F: exported through module table
+-- ============================================================
+analyze[[
+    local Foo = {}
+    Foo.__index = Foo
+    type Foo.@Name = "Foo"
+    type Foo.@SelfArgument = {
+        ["value"] = number,
+        @MetaTable = Foo,
+    }
+
+    function Foo:GetValue(): number
+        return self.value
+    end
+
+    local M = {}
+    local function new_foo<|T: any|>(): Foo.@SelfArgument
+        return setmetatable({value = 42} as Foo.@SelfArgument, Foo)
+    end
+    M.new = new_foo
+
+    local f = M.new<|string|>()
+    local v = f:GetValue()
+    attest.equal(v, _ as number)
+]]