Ensure fidlc is built, for instance
fx ninja -C out/default.zircon host-x64-linux-clang/obj/tools/fidl/fidlc host-x64-linux-clang/obj/system/utest/fidl-compiler/fidl-compiler-test
Then run the regen.sh script:
fx exec zircon/tools/fidl/testdata/regen.sh
This script runs fidlc on all of the inputs in the typestest/ directory, and outputs them into the goldens/ directory. The json_generator_tests are a fidlc unit test that will ensure that the output inside goldens/ matches the current state of the fidl compiler.
Each “input” in typestest/ corresponds to a single json output file in goldens/, and can take one of two possible forms:
foo.fidl which gets converted to foo.jsonfoo which gets converted to foo.json. This directory must contain:order.txt file that describes the dependency ordering of the files in this directory. For example, for a library foo that consists of two fidl files a.fidl and b.fidl where a.fidl depends on b.fidl, order.txt would consist of two lines, the first being b.fidl and the second being a.fidl.Currently json_generator_tests.cc only supports a “linked list” shaped dependency tree, where each fidl file depends on only the fidl file in the line above it (except for the first fidl file which has no dependencies)
Note that you must rebuild fidl-compiler-test after regenerating goldens for the updated goldens to be used in the test.