limit error message for type dismatch

resolve #1838

Author: sumneko

changelog.md

@@ -3,7 +3,10 @@
 ## 3.6.8
 * `NEW` command `lua.exportDocument` . VSCode will display this command in the right-click menu
 * `FIX` [#1831]
+* `FIX` [#1838]
+
 [#1831]: https://github.com/sumneko/lua-language-server/issues/1831
+[#1838]: https://github.com/sumneko/lua-language-server/issues/1838
 
 ## 3.6.7
 `2023-1-20`

script/vm/infer.lua

@@ -11,6 +11,7 @@ local vm       = require 'vm.vm'
 ---@field _lastView? string
 ---@field _lastViewUri? uri
 ---@field _lastViewDefault? any
+---@field _subViews? string[]
 local mt = {}
 mt.__index = mt
 mt._hasTable       = false
@@ -413,6 +414,7 @@ function mt:view(uri, default)
     end
 
     local array = {}
+    self._subViews = array
     for view in pairs(self.views) do
         if not self._drop[view] then
             array[#array+1] = view
@@ -471,6 +473,13 @@ function mt:eachView(uri)
     return next, self.views
 end
 
+---@param uri uri
+---@return string[]
+function mt:getSubViews(uri)
+    self:view(uri)
+    return self._subViews
+end
+
 ---@return string?
 function mt:viewLiterals()
     if not self.node then

script/vm/ref.lua

@@ -29,7 +29,10 @@ simpleSwitch = util.switch()
 
 ---@async
 local function searchInAllFiles(suri, searcher, notify)
+    await.delay()
+
     searcher(suri)
+    await.delay()
 
     local uris = {}
     for uri in files.eachFile(suri) do

script/vm/type.lua

@@ -301,7 +301,9 @@ function vm.isSubType(uri, child, parent, mark, errs)
                 end
             end
             if hasKnownType > 0 then
-                if errs and hasKnownType > 1 then
+                if  errs
+                and hasKnownType > 1
+                and #vm.getInfer(child):getSubViews(uri) > 1 then
                     errs[#errs+1] = 'TYPE_ERROR_CHILD_ALL_DISMATCH'
                     errs[#errs+1] = child
                     errs[#errs+1] = parent
@@ -376,7 +378,9 @@ function vm.isSubType(uri, child, parent, mark, errs)
             end
         end
         if hasKnownType > 0 then
-            if errs and hasKnownType > 1 then
+            if  errs
+            and hasKnownType > 1
+            and #vm.getInfer(parent):getSubViews(uri) > 1 then
                 errs[#errs+1] = 'TYPE_ERROR_PARENT_ALL_DISMATCH'
                 errs[#errs+1] = child
                 errs[#errs+1] = parent
@@ -703,6 +707,7 @@ local ErrorMessageMap = {
 ---@return string
 function vm.viewTypeErrorMessage(uri, errs)
     local lines = {}
+    local mark  = {}
     local index = 1
     while true do
         local name = errs[index]
@@ -741,8 +746,17 @@ function vm.viewTypeErrorMessage(uri, errs)
             index = index + 1
         end
         local line = lang.script(name, lparams)
-        lines[#lines+1] = '- ' .. line
+        if not mark[line] then
+            mark[line] = true
+            lines[#lines+1] = '- ' .. line
+        end
     end
     util.revertTable(lines)
-    return table.concat(lines, '\n')
+    if #lines > 15 then
+        lines[13] = ('...(+%d)'):format(#lines - 15)
+        table.move(lines, #lines - 2, #lines, 14)
+        return table.concat(lines, '\n', 1, 16)
+    else
+        return table.concat(lines, '\n')
+    end
 end

test/diagnostics/init.lua

@@ -47,6 +47,10 @@ function TEST(script, ...)
     end
 
     files.remove(TESTURI)
+
+    return function (callback)
+        callback(origins)
+    end
 end
 
 require 'diagnostics.common'

test/diagnostics/type-check.lua

@@ -1128,6 +1128,58 @@ local t = {
 }
 ]]
 
+TEST [[
+local x
+
+if X then
+    x = 'A'
+elseif X then
+    x = 'B'
+else
+    x = 'C'
+end
+
+local y = x
+
+<!y!> = nil
+]]
+(function (diags)
+    local diag = diags[1]
+    assert(diag.message == [[
+已显式定义变量的类型为 `string` ，不能再将其类型转换为 `nil`。
+- `nil` 无法匹配 `string`
+- 类型 `nil` 无法匹配 `string`]])
+end)
+
+
+TEST [[
+---@type 'A'|'B'|'C'|'D'|'E'|'F'|'G'|'H'|'I'|'J'|'K'|'L'|'M'|'N'|'O'|'P'|'Q'|'R'|'S'|'T'|'U'|'V'|'W'|'X'|'Y'|'Z'
+local x
+
+<!x!> = nil
+]]
+(function (diags)
+    local diag = diags[1]
+    assert(diag.message == [[
+已显式定义变量的类型为 `'A'|'B'|'C'|'D'|'E'...(+21)` ，不能再将其类型转换为 `nil`。
+- `nil` 无法匹配 `'A'|'B'|'C'|'D'|'E'...(+21)`
+- `nil` 无法匹配 `'A'|'B'|'C'|'D'|'E'...(+21)` 中的任何子类
+- 类型 `nil` 无法匹配 `'Z'`
+- 类型 `nil` 无法匹配 `'Y'`
+- 类型 `nil` 无法匹配 `'X'`
+- 类型 `nil` 无法匹配 `'W'`
+- 类型 `nil` 无法匹配 `'V'`
+- 类型 `nil` 无法匹配 `'U'`
+- 类型 `nil` 无法匹配 `'T'`
+- 类型 `nil` 无法匹配 `'S'`
+- 类型 `nil` 无法匹配 `'R'`
+- 类型 `nil` 无法匹配 `'Q'`
+...(+13)
+- 类型 `nil` 无法匹配 `'C'`
+- 类型 `nil` 无法匹配 `'B'`
+- 类型 `nil` 无法匹配 `'A'`]])
+end)
+
 config.remove(nil, 'Lua.diagnostics.disable', 'unused-local')
 config.remove(nil, 'Lua.diagnostics.disable', 'unused-function')
 config.remove(nil, 'Lua.diagnostics.disable', 'undefined-global')