stack: check go module after GOPATH

This is an hard call. Normally localgomod should never be inside GOPATH.

Minor forward looking v2 fixes.

Author: maruel

stack/context_test.go

@@ -1256,6 +1256,10 @@ func testPanicMismatched(t *testing.T, c *Context, b *bytes.Buffer, ppDir string
 	if b.String() != "GOTRACEBACK=all\npanic: 42\n\n" {
 		t.Fatalf("output: %q", b.String())
 	}
+	ver := ""
+	if !internaltest.IsUsingModules() {
+		ver = ""
+	}
 	want := []*Goroutine{
 		{
 			Signature: Signature{
@@ -1268,7 +1272,7 @@ func testPanicMismatched(t *testing.T, c *Context, b *bytes.Buffer, ppDir string
 							//
 							// Here the package name is "correct". There is no way to deduce
 							// this from the stack trace.
-							"github.com/maruel/panicparse/cmd/panic/internal/incorrect.Panic",
+							"github.com/maruel/panicparse"+ver+"/cmd/panic/internal/incorrect.Panic",
 							Args{},
 							pathJoin(ppDir, "internal", "incorrect", "correct.go"),
 							7),
@@ -1321,6 +1325,10 @@ func testPanicUTF8(t *testing.T, c *Context, b *bytes.Buffer, ppDir string) {
 	if b.String() != "GOTRACEBACK=all\npanic: 42\n\n" {
 		t.Fatalf("output: %q", b.String())
 	}
+	ver := ""
+	if !internaltest.IsUsingModules() {
+		ver = ""
+	}
 	want := []*Goroutine{
 		{
 			Signature: Signature{
@@ -1331,7 +1339,7 @@ func testPanicUTF8(t *testing.T, c *Context, b *bytes.Buffer, ppDir string) {
 							// This is important to note here the inconsistency in the Go
 							// runtime stack generator. The path is escaped, but symbols are
 							// not.
-							"github.com/maruel/panicparse/cmd/panic/internal/%c3%b9tf8.(*Strùct).Pànic",
+							"github.com/maruel/panicparse"+ver+"/cmd/panic/internal/%c3%b9tf8.(*Strùct).Pànic",
 							Args{Values: []Arg{{Value: 0xc0000b2e48}}},
 							// See TestCallUTF8 in stack_test.go for exercising the methods on
 							// Call in this situation.
@@ -1485,7 +1493,17 @@ func pstCount(s []panicwebSignatureType, t panicwebSignatureType) int {
 	return i
 }
 
+// identifyPanicwebSignature tries to assign one of the predefined signature to
+// the bucket provided.
+//
+// One challenge is that the path will be different depending if this test is
+// run within GOPATH or outside.
 func identifyPanicwebSignature(t *testing.T, b *Bucket, pwebDir string) panicwebSignatureType {
+	ver := ""
+	if !isInGOPATH {
+		ver = ""
+	}
+
 	// The first bucket (the one calling panic()) is deterministic.
 	if b.First {
 		if len(b.IDs) != 1 {
@@ -1511,7 +1529,7 @@ func identifyPanicwebSignature(t *testing.T, b *Bucket, pwebDir string) panicweb
 			t.Fatalf("suspicious: %#v", b)
 			return pstUnknown
 		}
-		if b.Stack.Calls[0].ImportPath() != "github.com/maruel/panicparse/cmd/panicweb/internal" {
+		if b.Stack.Calls[0].ImportPath() != "github.com/maruel/panicparse"+ver+"/cmd/panicweb/internal" {
 			t.Fatalf("suspicious: %#v", b)
 			return pstUnknown
 		}

stack/stack.go

@@ -363,16 +363,7 @@ func (c *Call) updateLocations(goroot, localgoroot, localgomod, gomodImportPath
 			goto done
 		}
 	}
-	// Go module path detection only works with stack traces created on the local
-	// file system.
-	if localgomod != "" {
-		if prefix := localgomod + "/"; strings.HasPrefix(c.SrcPath, prefix) {
-			c.RelSrcPath = gomodImportPath + "/" + c.SrcPath[len(prefix):]
-			c.LocalSrcPath = c.SrcPath
-			goto done
-		}
-	}
-	// Finally, check GOPATH.
+	// Check GOPATH.
 	// TODO(maruel): Sort for deterministic behavior?
 	for prefix, dest := range gopaths {
 		if p := prefix + "/src/"; strings.HasPrefix(c.SrcPath, p) {
@@ -387,6 +378,15 @@ func (c *Call) updateLocations(goroot, localgoroot, localgomod, gomodImportPath
 			goto done
 		}
 	}
+	// Go module path detection only works with stack traces created on the local
+	// file system.
+	if localgomod != "" {
+		if prefix := localgomod + "/"; strings.HasPrefix(c.SrcPath, prefix) {
+			c.RelSrcPath = gomodImportPath + "/" + c.SrcPath[len(prefix):]
+			c.LocalSrcPath = c.SrcPath
+			goto done
+		}
+	}
 done:
 	if !c.IsStdlib {
 		// Consider _test/_testmain.go as stdlib since it's injected by "go test".

stack/stack_test.go

@@ -12,7 +12,6 @@ import (
 	"os"
 	"runtime"
 	"strings"
-	"sync"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -387,6 +386,40 @@ func TestSignature_Less(t *testing.T) {
 
 //
 
+var (
+	goroot     string
+	gopaths    map[string]string
+	gomod      string
+	goimport   string
+	isInGOPATH bool
+)
+
+func init() {
+	goroot = runtime.GOROOT()
+	gopaths = map[string]string{}
+	for _, p := range getGOPATHs() {
+		gopaths[p] = p
+	}
+
+	// Assumes pwd == this directory.
+	pwd, err := os.Getwd()
+	if err != nil {
+		panic(err)
+	}
+	// Our internal functions work with '/' as path separator.
+	pwd = strings.Replace(pwd, "\\", "/", -1)
+	gomod, goimport = isGoModule(splitPath(pwd))
+
+	// When inside GOPATH, no version is added. When outside, the version path is
+	// added from the reading of module statement in go.mod.
+	for _, p := range getGOPATHs() {
+		if strings.HasPrefix(pwd, p) {
+			isInGOPATH = true
+			break
+		}
+	}
+}
+
 func newFunc(s string) Func {
 	return Func{Raw: s}
 }
@@ -395,30 +428,7 @@ func newCall(f string, a Args, s string, l int) Call {
 	return Call{Func: newFunc(f), Args: a, SrcPath: s, Line: l}
 }
 
-var (
-	local    sync.Once
-	goroot   string
-	gopaths  map[string]string
-	gomod    string
-	goimport string
-)
-
 func newCallLocal(f string, a Args, s string, l int) Call {
-	local.Do(func() {
-		goroot = runtime.GOROOT()
-		gopaths = map[string]string{}
-		for _, p := range getGOPATHs() {
-			gopaths[p] = p
-		}
-		// Assumes pwd == this directory.
-		pwd, err := os.Getwd()
-		if err != nil {
-			panic(err)
-		}
-		// Our internal functions work with '/' as path separator.
-		pwd = strings.Replace(pwd, "\\", "/", -1)
-		gomod, goimport = isGoModule(splitPath(pwd))
-	})
 	c := newCall(f, a, s, l)
 	c.updateLocations(goroot, goroot, gomod, goimport, gopaths)
 	if c.LocalSrcPath == "" || c.RelSrcPath == "" {