rmapshaper 0.4.6

Fixed a long-standing issue where units columns in sf objects would cause failures; all numeric columns of class "units" are now converted to numeric before running through mapshaper commands. (#116, thanks @Robinlovelace)
Added a default value for force_FC in apply_mapshaper_commands(). The default value is TRUE (#120, thanks @dblodgett-usgs)
Documentation fix in check_sys_mapshaper() - fixed description of return value (#117, thanks @dblodgett-usgs).
Included an example of setting memory allocation when using the system mapshaper in README (#114, thanks @baldeagle).

rmapshaper 0.4.5

Fixed a bug where functions would fail when there was a space in user’s tmpdir() path and sys = TRUE (#107)
Updated bundled mapshaper library to v 0.4.163, which fixed a bug in ms_erase (#110, #104, #112)
When sys = TRUE, now uses mapshaper-xl in the system call, allowing larger memory use. Default 8GB can be specified in new argument sys_mem (#94, #112)
Internally switched to using system2() over system() for flexibility

Add checks, a package startup message, and helpful errors for the case when a user has an old version of libv8 installed, as they do not support many aspects of modern JavaScript (ES6). This appears to only impact ms_erase() and ms_clip().
Using apply_mapshaper_commands() no longer deletes a file when used on a local file (#99, #100)

Added rgdal to Suggests so ms_clip and ms_erase can transform Spatial* objects when they have different CRSs.
When an input sf object is a tibble, the output is now now also a tibble, (#95, thanks @mdsumner)
Upgraded to mapshaper v0.4.107
Bumped minimum version of V8 to 3.0

Fixed a bug when using sys = TRUE would fail on Windows in some circumstances (#77)
Fixed an issue where running rmapshaper functions on sfc objects failed with sf v0.7

Added sys argument to allow the use of the system mapshaper if it’s installed (#61)

Upgraded to mapshaper v0.4.64 (#60)
sf::st_read() is now used throughout for reading from disk and from geojson strings, which allows for greater consistency and better performance.
Better handling of different column classes (#68, thanks @mdsumner)
Avoid stackoverflow caused by adding special geojson classes (#71, https://github.com/ropensci/geojsonio/issues/128)
The name of the sf column is now properly retained (#70)
Fixed issue where encoding/special characters were not preserved (#67)

Fixed a bug where converting geojson objects to sf failed with sf >= 0.5-6 (#64)

Methods for sf and sfc classes have been added (#46)
rmapshaperid column is only retained if it is the only column, otherwise it’s dropped.
ms_innerlines returns only the geometry for sf and Spatial*DataFrame classes. (#57)
ms_dissolve gains a weight argument for generating weighted centroids of dissolved points. (#39)

Added snap_interval to ms_simplify() (#43, @nikolai-b)
Bug-fix: Respect drop_null_geometries argument in ms_simplify.geo_list() (#45, @nikolai-b)
Add Kent Russell (@timelyportfolio) to authors list for his JavaScript expertise and advice
Add Matthew Bloch (@mbloch) to authors list as mapshaper copyright holder
Update mapshaper to version 0.3.41
A V8 session is now launched once per function call and destroyed when the function exits, rather than created on package load and retained for the entire session (#49)
Column classes are now restored after being sent through mapshaper functions (#46)
Fixed a bug where very small values of keep in ms_simplify() were converted to scientific notation (#48)
Added weighting argument to ms_simplify() (#27)
Added remove_slivers argument in ms_clip() and ms_erase()