Add new -default-case-required flag #15

	on: [push, pull_request]
	name: ci
	jobs:
	all:
	strategy:
	matrix:
	go-version: [1.18, 1.19, 1.x]
	os: [ubuntu-latest, macos-latest, windows-latest]
	runs-on: ${{ matrix.os }}

	steps:
	- name: install go
	uses: actions/setup-go@v2
	with:
	go-version: ${{ matrix.go-version }}

	- name: checkout code
	uses: actions/checkout@v2

	- name: build
	run: make build

	# For earlier go versions, staticcheck build fails due to:
	#
	# ../../../go/pkg/mod/honnef.co/go/[email protected]/go/ir/builder.go:36:2:
	# //go:build comment without // +build comment
	#
	# or due to:
	#
	# ../../../go/pkg/mod/honnef.co/go/[email protected]/staticcheck/lint.go:4030:36:
	# sel.Obj().(types.Func).Origin undefined (type types.Func has no field
	# or method Origin)
	# note: module requires Go 1.19
	#
	- name: install vet tools (go 1.19 or later)
	if: ${{ matrix.go-version >= '1.19' }}
	run: make install-vet

	- name: vet (go 1.19 or later)
	if: ${{ matrix.go-version >= '1.19' }}
	run: make vet

	- name: test
	run: make test

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