Convert error type assertions to errors.As(...)

This is best practice, unless the exact type is really required.

Signed-off-by: Tom Wieczorek <[email protected]>

Author: twz123

internal/pkg/sysinfo/probes/linux/cgroups.go

@@ -19,6 +19,7 @@ limitations under the License.
 package linux
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"sync"
@@ -80,8 +81,9 @@ func (c *CgroupsProbes) probe(reporter probes.Reporter) error {
 }
 
 func reportCgroupSystemErr(reporter probes.Reporter, d probes.ProbeDesc, err error) error {
-	if detectionFailed, ok := err.(cgroupFsDetectionFailed); ok {
-		return reporter.Reject(d, detectionFailed, "")
+	var detectionFailedErr cgroupFsDetectionFailed
+	if errors.As(err, &detectionFailedErr) {
+		return reporter.Reject(d, detectionFailedErr, "")
 	}
 
 	return reporter.Error(d, err)

internal/pkg/sysinfo/probes/linux/kernel.go

@@ -206,8 +206,9 @@ func (k *kConfigProbe) DisplayName() string {
 func (k *kConfigProbe) Probe(reporter probes.Reporter) error {
 	option, err := k.probeConfig(k.kConfig)
 	if err != nil {
-		if err, notFound := err.(*noKConfigsFound); notFound {
-			return reporter.Warn(k, err, "")
+		var notFoundErr *noKConfigsFound
+		if errors.As(err, &notFoundErr) {
+			return reporter.Warn(k, notFoundErr, "")
 		}
 		return reporter.Error(k, err)
 	}

internal/pkg/sysinfo/probes/linux/kernel_test.go

@@ -117,8 +117,9 @@ func TestKConfigProber(t *testing.T) {
 
 		option, err := probeKConfig(ensureKConfig("I_CERTAINLY_DONT_EXIST"))
 		assert.Equal(t, option, kConfigUnknown)
-		if _, ok := err.(*noKConfigsFound); ok {
-			t.Log("system doesn't expose its kernel config")
+		var notFoundErr *noKConfigsFound
+		if errors.As(err, &notFoundErr) {
+			t.Logf("System doesn't seem to expose its kernel config: %v", err)
 		} else {
 			assert.NoError(t, err)
 		}

internal/pkg/sysinfo/probes/memory.go

@@ -16,7 +16,10 @@ limitations under the License.
 
 package probes
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+)
 
 // AssertTotalMemory asserts a minimum amount of system RAM.
 func AssertTotalMemory(parent ParentProbe, min uint64) {
@@ -39,7 +42,8 @@ type assertTotalMem struct {
 func (a *assertTotalMem) Probe(reporter Reporter) error {
 	desc := NewProbeDesc("Total memory", a.path)
 	if totalMemory, err := a.probeTotalMemory(); err != nil {
-		if unsupportedErr, unsupported := err.(probeUnsupported); unsupported {
+		var unsupportedErr probeUnsupported
+		if errors.As(err, &unsupportedErr) {
 			return reporter.Warn(desc, unsupportedErr, "")
 		}
 		return reporter.Error(desc, err)

pkg/kubernetes/watch/watcher.go

@@ -18,6 +18,7 @@ package watch
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"reflect"
 	"time"
@@ -393,9 +394,10 @@ func retry(ctx context.Context, errorCallback ErrorCallback, runWatch func(conte
 			return nil
 		}
 
-		if err, ok := err.(conditionError); ok {
+		var condErr conditionError
+		if errors.As(err, &condErr) {
 			// The user-specified condition returned an error.
-			return err.error
+			return condErr.error
 		}
 
 		if ctx.Err() != nil {