1 files changed, 474 insertions, 0 deletions
diff --git a/test/diagnostics/assign-type-mismatch.lua b/test/diagnostics/assign-type-mismatch.lua
new file mode 100644
index 00000000..d4632563
--- /dev/null
+++ b/test/diagnostics/assign-type-mismatch.lua
@@ -0,0 +1,474 @@
+local config = require 'config'
+
+TEST [[
+local m = {}
+
+---@type integer[]
+m.ints = {}
+]]
+
+TEST [[
+---@class A
+---@field x A
+
+---@type A
+local t
+
+t.x = {}
+]]
+
+TEST [[
+---@class A
+---@field x integer
+
+---@type A
+local t
+
+<!t.x!> = true
+]]
+
+TEST [[
+---@class A
+---@field x integer
+
+---@type A
+local t
+
+---@type boolean
+local y
+
+<!t.x!> = y
+]]
+
+TEST [[
+---@class A
+local m
+
+m.x = 1
+
+---@type A
+local t
+
+<!t.x!> = true
+]]
+
+TEST [[
+---@class A
+local m
+
+---@type integer
+m.x = 1
+
+<!m.x!> = true
+]]
+
+TEST [[
+---@class A
+local mt
+
+---@type integer
+mt.x = 1
+
+function mt:init()
+    <!self.x!> = true
+end
+]]
+
+TEST [[
+---@class A
+---@field x integer
+
+---@type A
+local t = {
+    <!x!> = true
+}
+]]
+
+TEST [[
+---@type boolean[]
+local t = {}
+
+t[5] = nil
+]]
+
+TEST [[
+---@type table<string, true>
+local t = {}
+
+t['x'] = nil
+]]
+
+TEST [[
+local t = { true }
+
+t[1] = nil
+]]
+
+TEST [[
+---@class A
+local t = {
+    x = 1
+}
+
+<!t.x!> = true
+]]
+
+TEST [[
+---@type number
+local t
+
+t = 1
+]]
+
+TEST [[
+---@type number
+local t
+
+---@type integer
+local y
+
+t = y
+]]
+
+TEST [[
+---@class A
+local m
+
+---@type number
+m.x = 1
+
+<!m.x!> = {}
+]]
+
+TEST [[
+local n
+
+if G then
+    n = {}
+else
+    n = nil
+end
+
+local t = {
+    x = n,
+}
+]]
+
+TEST [[
+---@type boolean[]
+local t = {}
+
+---@type boolean?
+local x
+
+t[#t+1] = x
+]]
+
+TEST [[
+---@type number
+local n
+---@type integer
+local i
+
+<?i?> = n
+]]
+
+config.set(nil, 'Lua.type.castNumberToInteger', true)
+TEST [[
+---@type number
+local n
+---@type integer
+local i
+
+i = n
+]]
+
+config.set(nil, 'Lua.type.castNumberToInteger', false)
+TEST [[
+---@type number|boolean
+local nb
+
+---@type number
+local n
+
+<?n?> = nb
+]]
+
+config.set(nil, 'Lua.type.weakUnionCheck', true)
+TEST [[
+---@type number|boolean
+local nb
+
+---@type number
+local n
+
+n = nb
+]]
+
+config.set(nil, 'Lua.type.weakUnionCheck', false)
+TEST [[
+---@class Option: string
+
+---@param x Option
+local function f(x) end
+
+---@type Option
+local x = 'aaa'
+
+f(x)
+]]
+config.set(nil, 'Lua.type.weakUnionCheck', true)
+
+TEST [[
+---@type number
+local <!x!> = 'aaa'
+]]
+TEST [[
+---@class X
+
+---@class A
+local mt = G
+
+---@type X
+mt._x = nil
+]]
+config.set(nil, 'Lua.type.weakUnionCheck', false)
+
+config.set(nil, 'Lua.type.weakNilCheck', true)
+TEST [[
+---@type number?
+local nb
+
+---@type number
+local n
+
+n = nb
+]]
+
+TEST [[
+---@type number|nil
+local nb
+
+---@type number
+local n
+
+n = nb
+]]
+config.set(nil, 'Lua.type.weakNilCheck', false)
+
+TEST [[
+---@class A
+local a = {}
+
+---@class B
+local <!b!> = a
+]]
+
+TEST [[
+---@class A
+local a = {}
+
+---@class B: A
+local b = a
+]]
+
+TEST [[
+---@class A
+local a = {}
+a.__index = a
+
+---@class B: A
+local b = setmetatable({}, a)
+]]
+
+TEST [[
+---@class A
+local a = {}
+
+---@class B: A
+local b = setmetatable({}, {__index = a})
+]]
+
+TEST [[
+---@class A
+local a = {}
+
+---@class B
+local <!b!> = setmetatable({}, {__index = a})
+]]
+
+TEST [[
+---@class A
+---@field x number?
+local a
+
+---@class B
+---@field x number
+local b
+
+b.x = a.x
+]]
+
+TEST [[
+
+---@class A
+---@field x number?
+local a
+
+---@type number
+local t
+
+t = a.x
+]]
+
+TEST [[
+local mt = {}
+mt.x = 1
+mt.x = nil
+]]
+
+config.set(nil, 'Lua.type.weakUnionCheck', true)
+TEST [[
+---@type number
+local x = G
+]]
+
+TEST [[
+---@generic T
+---@param x T
+---@return T
+local function f(x)
+    return x
+end
+]]
+config.set(nil, 'Lua.type.weakUnionCheck', false)
+
+
+TEST [[
+---@alias test boolean
+
+---@type test
+local <!test!> = 4
+]]
+
+TEST [[
+---@class MyClass
+local MyClass = {}
+
+function MyClass:new()
+    ---@class MyClass
+    local myObject = setmetatable({
+        initialField = true
+    }, self)
+
+    print(myObject.initialField)
+end
+]]
+
+TEST [[
+---@class T
+local t = {
+    x = nil
+}
+
+t.x = 1
+]]
+
+TEST [[
+---@type {[1]: string, [10]: number, xx: boolean}
+local t = {
+    <!true!>,
+    <![10]!> = 's',
+    <!xx!> = 1,
+}
+]]
+
+TEST [[
+---@type boolean[]
+local t = { <!1!>, <!2!>, <!3!> }
+]]
+
+TEST [[
+---@type boolean[]
+local t = { true, false, nil }
+]]
+
+TEST [[
+---@type boolean|nil
+local x
+
+---@type boolean[]
+local t = { true, false, x }
+]]
+
+TEST [[
+---@enum Enum
+local t = {
+    x = 1,
+    y = 2,
+}
+
+---@type Enum
+local y
+
+---@type integer
+local x = y
+]]
+
+TEST [[
+---@type string|string[]|string[][]
+local t = {{'a'}}
+]]
+
+TEST [[
+local A = "Hello"
+local B = "World"
+
+---@alias myLiteralAliases `A` | `B`
+
+---@type myLiteralAliases
+local x = A
+]]
+
+TEST [[
+local enum = { a = 1, b = 2 }
+
+---@type { [integer] : boolean }
+local t = {
+    <![enum.a]!> = 1,
+    <![enum.b]!> = 2,
+    <![3]!> = 3,
+}
+]]
+
+TEST [[
+---@class SomeClass
+---@field [1] string
+-- ...
+
+---@param some_param SomeClass|SomeClass[]
+local function some_fn(some_param) return end
+
+some_fn { { "test" } } -- <- diagnostic: "Cannot assign `table` to `string`."
+]]
+
+TEST [[
+---@type string[]
+local arr = {
+    <!3!>,
+}
+]]
+
+TEST [[
+---@type (string|boolean)[]
+local arr2 = {
+    <!3!>, -- no warnings
+}
+]]
+
+TEST [[
+local t = {}
+t.a = 1
+t.a = 2
+return t
+]]