Split cgroups test into 3 tests

arbnode/resourcemanager/resource_management_test.go

@@ -31,52 +31,62 @@ func updateFakeCgroupFiles(c *cgroupsMemoryLimitChecker, limit, usage, inactive
 	if err != nil {
 		return err
 	}
-	if _, err = fmt.Fprintf(statsFile, `total_cache 1029980160
+	_, err = fmt.Fprintf(statsFile, `total_cache 1029980160
 total_rss 1016209408
 total_inactive_file %d
 total_active_file 321544192
-`, inactive); err != nil {
-		return err
-	}
-	return nil
+`, inactive)
+	return err
 }
 
-func TestCgroupsMemoryLimit(t *testing.T) {
-	cgroupDir := t.TempDir()
-	testFiles := cgroupsMemoryFiles{
+func makeCgroupsTestDir(cgroupDir string) cgroupsMemoryFiles {
+	return cgroupsMemoryFiles{
 		limitFile:  cgroupDir + "/memory.limit_in_bytes",
 		usageFile:  cgroupDir + "/memory.usage_in_bytes",
 		statsFile:  cgroupDir + "/memory.stat",
 		inactiveRe: regexp.MustCompile(`total_inactive_file (\d+)`),
 	}
+}
 
+func TestCgroupsFailIfCantOpen(t *testing.T) {
+	testFiles := makeCgroupsTestDir(t.TempDir())
 	c := newCgroupsMemoryLimitChecker(testFiles, 95)
-	_, err := c.isLimitExceeded()
-	if err == nil {
-		t.Error("Should fail open if can't read files")
+	var err error
+	if _, err = c.isLimitExceeded(); err == nil {
+		t.Fatal("Should fail open if can't read files")
 	}
+}
 
-	err = updateFakeCgroupFiles(c, 1000, 1000, 51)
-	if err != nil {
-		t.Error(err)
+func TestCgroupsLimitNotExceeded(t *testing.T) {
+	testFiles := makeCgroupsTestDir(t.TempDir())
+	c := newCgroupsMemoryLimitChecker(testFiles, 95)
+
+	var err error
+	if err = updateFakeCgroupFiles(c, 1000, 1000, 51); err != nil {
+		t.Fatal(err)
 	}
 	exceeded, err := c.isLimitExceeded()
 	if err != nil {
-		t.Error(err)
+		t.Fatal(err)
 	}
 	if exceeded {
-		t.Error("Expected under limit")
+		t.Fatal("Expected under limit")
 	}
+}
 
-	err = updateFakeCgroupFiles(c, 1000, 1000, 50)
-	if err != nil {
-		t.Error(err)
+func TestCgroupsLimitExceeded(t *testing.T) {
+	testFiles := makeCgroupsTestDir(t.TempDir())
+	c := newCgroupsMemoryLimitChecker(testFiles, 95)
+
+	var err error
+	if err = updateFakeCgroupFiles(c, 1000, 1000, 50); err != nil {
+		t.Fatal(err)
 	}
-	exceeded, err = c.isLimitExceeded()
+	exceeded, err := c.isLimitExceeded()
 	if err != nil {
-		t.Error(err)
+		t.Fatal(err)
 	}
 	if !exceeded {
-		t.Error("Expected over limit")
+		t.Fatal("Expected over limit")
 	}
 }