From 22d978fe698535bc14085b58a70639de1f930760 Mon Sep 17 00:00:00 2001
From: Jan Semmelink <jan@uafrica.com>
Date: Fri, 17 Sep 2021 14:13:24 +0200
Subject: [PATCH] Added readme and test for nexted Is()
---
errors/README.md | 6 ++++++
errors/errors_test.go | 24 ++++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/errors/README.md b/errors/README.md
index 9190b1e..39be72b 100644
--- a/errors/README.md
+++ b/errors/README.md
@@ -175,3 +175,9 @@ This function can be used also for logging to determine the caller from the runt
## func Stack()
This function is similar to Caller() but reports an array of callers, not only one.
+
+## func Is()
+
+You can compare a message with errors.Is() to some error specification.
+It will look at the error or any cause to match the spec.
+The spec is the error message.
\ No newline at end of file
diff --git a/errors/errors_test.go b/errors/errors_test.go
index f9a8e2c..75bf7a3 100644
--- a/errors/errors_test.go
+++ b/errors/errors_test.go
@@ -109,6 +109,23 @@ func TestIs(t *testing.T) {
t.Logf("n=%d worked", n)
}
}
+
+ //same but err is wrapped deeper
+ for n := 0; n <= 4; n++ {
+ if err := UserExists(n); err != nil {
+ switch {
+ case errors.Is(err, errNotFound):
+ t.Logf("u=%d failed with NOT FOUND", n)
+ case errors.Is(err, errDisabled):
+ t.Logf("u=%d failed because disabled", n)
+ default:
+ t.Logf("u=%d failed for unknown cause: %+v", n, err)
+ }
+ } else {
+ t.Logf("u=%d worked", n)
+ }
+ }
+
}
var (
@@ -130,3 +147,10 @@ func ReadDb(x int) error {
return errors.Errorf("invalid x=%d", x)
}
}
+
+func UserExists(u int) error {
+ if err := ReadDb(u); err != nil {
+ return errors.Wrapf(err, "cannot read user %d", u)
+ }
+ return nil
+}
--
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