Refine boolean-context diagnostics

Author: kyoh86

script/core/diagnostics/boolean-context.lua

@@ -23,18 +23,32 @@ local function isBooleanOnly(infer, uri)
     if infer:hasAny(uri) or infer:hasUnknown(uri) then
         return nil
     end
-    local hasBoolean = infer:hasType(uri, 'boolean')
-    if not hasBoolean then
-        return false
-    end
     for view in infer:eachView(uri) do
-        if view ~= 'boolean' then
+        if view ~= 'boolean'
+        and view ~= 'true'
+        and view ~= 'false' then
             return false
         end
     end
     return true
 end
 
+---@param source parser.object?
+---@return boolean
+local function isConditionFilter(source)
+    if not source or not source.parent then
+        return false
+    end
+    local parent = source.parent
+    if parent.type ~= 'ifblock'
+    and parent.type ~= 'elseifblock'
+    and parent.type ~= 'while'
+    and parent.type ~= 'repeat' then
+        return false
+    end
+    return parent.filter == source
+end
+
 ---@param source parser.object?
 ---@param uri uri
 ---@param callback fun(result: diag.result)
@@ -90,6 +104,11 @@ return function (uri, callback)
         if op ~= 'and' and op ~= 'or' then
             return
         end
+        if isConditionFilter(source) then
+            checkExpression(source[1], uri, callback)
+            checkExpression(source[2], uri, callback)
+            return
+        end
         checkExpression(source[1], uri, callback)
     end)
 end

script/vm/node.lua

@@ -148,9 +148,6 @@ end
 ---Almost an inverse of alwaysTruthy, but strict about "any" and "unknown" types.
 ---@return boolean
 function mt:alwaysFalsy()
-    if self.optional then
-        return false
-    end
     if #self == 0 then
         return false
     end

test/diagnostics/boolean-context.lua

@@ -19,6 +19,10 @@ local y = <!d!> and "4"
 local e
 if e then end
 
+---@type true
+local t
+if t then end
+
 ---@type boolean|nil
 local g
 if <!g!> then end
@@ -27,6 +31,10 @@ if <!g!> then end
 local h
 if <!h!> and true then end
 
+---@type number
+local i
+if true and <!i!> then end
+
 ---@type any
 local f
 local z = f or "3"