cue/load: don't load from $PWD in the integration tests

This required us to have a "test.cue" file in cue/load even though
it has nothing to do with the non-test code in cue/load.
That was confusing to me in the past, and such files belong in testdata.
We already have a "hello" package there too, so we can just use it.

TestLoadInstancesConcurrent ignored errors, so removing test.cue
would have silently made it do nothing. Make it more robust first.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I16abcee509afb677bc4f66d55dc01cd5eed58524
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1194419
Unity-Result: CUE porcuepine <[email protected]>
Reviewed-by: Paul Jolly <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

cue/load/import_test.go

@@ -16,7 +16,6 @@ package load
 
 import (
 	"fmt"
-	"os"
 	"path/filepath"
 	"reflect"
 	"testing"
@@ -81,12 +80,7 @@ func TestMultiplePackageImport(t *testing.T) {
 }
 
 func TestLocalDirectory(t *testing.T) {
-	cwd, err := os.Getwd()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	p, err := getInst(".", cwd)
+	p, err := getInst(".", testdata("testmod", "hello"))
 	if err != nil {
 		t.Fatal(err)
 	}

cue/load/loader_test.go

@@ -466,17 +466,20 @@ func TestLoadInstancesConcurrent(t *testing.T) {
 	// This test is designed to fail when run with the race detector
 	// if there's an underlying race condition.
 	// See https://cuelang.org/issue/1746
-	race(func() {
-		Instances([]string{"."}, nil)
+	race(t, func() error {
+		_, err := getInst(".", testdata("testmod", "hello"))
+		return err
 	})
 }
 
-func race(f func()) {
+func race(t *testing.T, f func() error) {
 	var wg sync.WaitGroup
 	for i := 0; i < 2; i++ {
 		wg.Add(1)
 		go func() {
-			f()
+			if err := f(); err != nil {
+				t.Error(err)
+			}
 			wg.Done()
 		}()
 	}