Support e2e-go tests when repo is not installed in GOPATH. (#3949)

Running e2e go tests fails when the repo is not cloned inside the GOPATH.
This change looks up the current directory using runtime.Caller
as an alternative to hard coding the GOPATH location.

test/framework/fixtures/baseFixture.go

@@ -20,6 +20,8 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"path"
+	"runtime"
 	"testing"
 
 	"github.com/algorand/go-algorand/config"
@@ -35,6 +37,15 @@ type baseFixture struct {
 	instance    Fixture
 }
 
+func getTestDir() string {
+	_, filename, _, ok := runtime.Caller(0)
+	if ok {
+		return path.Join(path.Dir(filename), "..", "..")
+	}
+	// fallback to the legacy GOPATH location.
+	return os.ExpandEnv("${GOPATH}/src/github.com/algorand/go-algorand/test/")
+}
+
 func (f *baseFixture) initialize(instance Fixture) {
 	f.instance = instance
 	f.Config = config.Protocol
@@ -49,7 +60,7 @@ func (f *baseFixture) initialize(instance Fixture) {
 	}
 	f.testDataDir = os.Getenv("TESTDATADIR")
 	if f.testDataDir == "" {
-		f.testDataDir = os.ExpandEnv("${GOPATH}/src/github.com/algorand/go-algorand/test/testdata")
+		f.testDataDir = path.Join(getTestDir(), "testdata")
 	}
 }
 

test/framework/fixtures/expectFixture.go

@@ -25,7 +25,6 @@ import (
 	"path"
 	"path/filepath"
 	"regexp"
-	"runtime"
 	"strings"
 	"testing"
 
@@ -58,9 +57,7 @@ func (ef *ExpectFixture) initialize(t *testing.T) (err error) {
 	}
 	ef.testDataDir = os.Getenv("TESTDATADIR")
 	if ef.testDataDir == "" {
-		// Default to test/testdata in the source tree being tested
-		_, path, _, _ := runtime.Caller(0)
-		ef.testDataDir = filepath.Join(filepath.Dir(path), "../../testdata")
+		ef.testDataDir = filepath.Join(getTestDir(), "testdata")
 	}
 
 	ef.testFilter = os.Getenv("TESTFILTER")