Use Go 1.13 error features

* Use `errors.Is()` for unwrapping errors.
* Use `%w` error verb in internal error formatting.

Signed-off-by: Ben Kochie <superq@gmail.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/collector/textfile.go b/collector/textfile.go
index 64165e6..50c1807 100644
--- a/collector/textfile.go
+++ b/collector/textfile.go
@@ -238,14 +238,14 @@ func (c *textFileCollector) processFile(name string, ch chan<- prometheus.Metric
         path := filepath.Join(c.path, name)
         f, err := os.Open(path)
         if err != nil {
-                return nil, fmt.Errorf("failed to open textfile data file %q: %v", path, err)
+                return nil, fmt.Errorf("failed to open textfile data file %q: %w", path, err)
         }
         defer f.Close()
 
         var parser expfmt.TextParser
         families, err := parser.TextToMetricFamilies(f)
         if err != nil {
-                return nil, fmt.Errorf("failed to parse textfile data from %q: %v", path, err)
+                return nil, fmt.Errorf("failed to parse textfile data from %q: %w", path, err)
         }
 
         if hasTimestamps(families) {
@@ -267,7 +267,7 @@ func (c *textFileCollector) processFile(name string, ch chan<- prometheus.Metric
         // a failure does not appear fresh.
         stat, err := f.Stat()
         if err != nil {
-                return nil, fmt.Errorf("failed to stat %q: %v", path, err)
+                return nil, fmt.Errorf("failed to stat %q: %w", path, err)
         }
 
         t := stat.ModTime()