The program fidl_api_diff computes the difference between two FIDL API surfaces as described by the FIDL API summary JSON format.
The first set, //tools, is needed to ensure that the testing utilities are present.
fx set core.qemu-x64 --auto-dir \ --with=//tools \ --with=//tools/fidl
fx build tools/fidl/fidl_api_diff
fx test tools/fidl/fidl_api_diff
The following script demonstrates the use of the program for diffing an API of an in-tree FIDL library.
#!/bin/bash
readonly _build_dir="$(fx get-build-dir)"
mkdir -p "${HOME}/tmp"
fx build tools/fidl
"${_build_dir}/host_x64/fidl_api_summarize" \
--before-file "$HOME/tmp/before.api_summarize.json" \
--after-file "$HOME/tmp/after.api_summarize.json" \
--api-diff-file "$HOME/tmp/result.api_diff.json" \
"${@}"