What version of Go are you using (go version)?

$ go version
go version go1.14 darwin/amd64

Does this issue reproduce with the latest release?

Yes, but this is also a feature request. 😄

What operating system and processor architecture are you using (go env)?

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/bflad/Library/Caches/go-build"
GOENV="/Users/bflad/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/bflad/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.14/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.14/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/bflad/src/github.com/terraform-providers/terraform-provider-aws/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/w8/05f3x02n27x72g0mc2jy6_180000gp/T/go-build629459130=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

Attempting to test an *analysis.Analyzer that reports a Diagnostic with SuggestedFixes and TextEdits, e.g.

			pass.Report(analysis.Diagnostic{
				Pos:     selectorExpr.Pos(),
				End:     selectorExpr.End(),
				Message: fmt.Sprintf("%s: deprecated %s should be replaced with %s", analyzerName, selectorExprBuf.String(), newSelectorExprBuf.String()),
				SuggestedFixes: []analysis.SuggestedFix{
					{
						Message: "Replace",
						TextEdits: []analysis.TextEdit{
							{
								Pos:     selectorExpr.Pos(),
								End:     selectorExpr.End(),
								NewText: newSelectorExprBuf.Bytes(),
							},
						},
					},
				},
			})

What did you expect to see?

The ability or the framework to verify potential code changes via TextEdits.

What did you see instead?

Seems like there is not a native or built-in way to test these. I wrote together a proof of concept implementation that does the following:

• Takes a source directory (e.g. testdata/src/a) and copies to a temporary directory
• Wraps the Analyzer in a singlechecker.Main and re-executes the test with the -fix flag
• Compares expected directory (e.g. testdata/src/a_fixed) file contents with "fixed" temporary directory file contents

Full code: https://github.com/bflad/tfproviderlint/blob/master/helper/analysisfixtest/analysisfixtest.go

Testing implementation matches analysistest.Run:

func TestAnalyzerFixes(t *testing.T) {
	testdata := analysistest.TestData()
	analysisfixtest.Run(t, testdata, V008.Analyzer, "a")
}

Since the -fix flag is only handled by the multichecker/singlechecker drivers, this would be improved with #31897 (x/tools/go/analysis: provide driver for running analysis programmatically), rather than wrapping the Analyzer in a self-executing a child process.

It would be wonderful if functionality like this could be baked into go/analysis though! Thank you for your consideration.