version-1-to-2-guide.md

Migration guide to upgrade from version 1 to version 2

Explanation

In version 2.X, modern-async had a major re-design of the API. This re-design occured with the following goals:

• Avoiding function naming conflict with popular libraries (notably lodash)
• Simplifying the API by removing duplicate functions
• Proposing safer default parameters regarding concurrency handling

It can be noted that version 1.X will still be supported for a reasonable amount of time regarding bug fixes.

How to migrate ?

In order to migrate from version 1.X to version 2.X you should check the following points:

• Most functions were renamed to add an async prefix. Example: map => asyncMap.
• All functions that had three variants ("normal", Limit and Series) were simplified to have only 1 function. That function takes a queueOrConcurrency argument like the old Limit variant, except that argument now has a default value of 1. Here is how to change these function calls:
  • If you used the Limit variant, just rename it to the new name. The arguments will remain compatible. Example: mapLimit(a, b, concurreny) => asyncMap(a, b, concurreny).
  • If you used the Series variant, also rename it to the new name. The arguments will also remain compatible. Example: mapSeries(a, b) => asyncMap(a, b).
  • If you used the "normal" variant (with unlimited concurrency), you must pass Numbers.POSITIVE_INFINITY as the queueOrConcurrency argument. Example: map(a, b) => asyncMap(a, b, Number.POSITIVE_INFINITY). (You should also consider not using infinite concurrency anymore as it tends to be a bad idea in most real-life applications.)