fix(map) setdefault will now honor a 'false' value

2 files changed, 14 insertions, 4 deletions

diff --git a/lua/pl/Map.lua b/lua/pl/Map.lua
index 2624dc8..572b22a 100644
--- a/lua/pl/Map.lua
+++ b/lua/pl/Map.lua
@@ -55,10 +55,17 @@ function Map:items()
     return ls
 end
 
---- Will return the existing value, or if it doesn't exist it will set
--- a default value and return it.
-function Map:setdefault(key, defaultval)
-   return self[key] or self:set(key,defaultval) or defaultval
+--- set a value in the map if it doesn't exist yet.
+-- @param key the key
+-- @param default value to set
+-- @return the value stored in the map (existing value, or the new value)
+function Map:setdefault(key, default)
+    local val = self[key]
+    if val ~= nil then
+        return val
+    end
+    self:set(key,default)
+   return default
 end
 
 --- size of map.
diff --git a/tests/test-map.lua b/tests/test-map.lua
index 93e511a..1c0bee6 100644
--- a/tests/test-map.lua
+++ b/tests/test-map.lua
@@ -78,6 +78,9 @@ asserteq(
       {'gamma', 3},
     }
 )
+v = m:set("alpha", false)
+v = m:setdefault("alpha", true)   -- falsy value should not be altered
+asserteq(false, m:get("alpha"))