bench-object-updates
Just a little Friday afternoon project to compare strategies for merging objects in JS.
Each benchmark starts with a 1000-item base object and merges a 10-item "update" into it. It does this 100,000 times.
I'll save you the bother of cloning and running. Here's the results on my crappy lappy:
Some irrelevant tests...
doing nothing took 13ms
Array#concat (no uniq) took 60ms
Array spread (no uniq) took 1820ms
mutative tests
for-loop mutation took 35ms
Object.assign mutation took 36ms
non-mutative tests
spread operator copying took 6800ms
Object.assign copying took 5880ms
Array#concat + uniq took 3980ms
immutable-js took 230ms
So yeah, for-loop mutation and Object.assign are BLAZING fast. Stylistically I prefer Object.assign.
All the immutable versions are a lot slower but Immutable is back in the same kind of ball pond as the mutative versions.
Also interesting side-note that concatenating two arrays and then uniq'ing (using lodash's uniq function) is quicker than copying out the objects with either Object.assign or the spread operator, so if your only goal is deduplication it might work.