osutil.GetenvBool now takes an extra optional, argument

canonical · Jan 12, 2017 · a6b25e6 · a6b25e6
1 parent dea104c
commit a6b25e6
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Showing 2 changed files with 41 additions and 5 deletions.
diff --git a/osutil/env.go b/osutil/env.go
@@ -24,16 +24,27 @@ import (
 	"strconv"
 )
 
-// GetenvBool returns whether the given key may be considered "set" in the environment
-// (i.e. it is set to one of "1", "true", etc)
-func GetenvBool(key string) bool {
+// GetenvBool returns whether the given key may be considered "set" in the
+// environment (i.e. it is set to one of "1", "true", etc).
+//
+// An optional second argument can be provided, which determines how to
+// treat missing or unparsable values; default is to treat them as false.
+func GetenvBool(key string, dflt ...bool) bool {
 	val := os.Getenv(key)
 	if val == "" {
+		if len(dflt) > 0 {
+			return dflt[0]
+		}
+
 		return false
 	}
 
 	b, err := strconv.ParseBool(val)
 	if err != nil {
+		if len(dflt) > 0 {
+			return dflt[0]
+		}
+
 		return false
 	}
 

diff --git a/osutil/env_test.go b/osutil/env_test.go
@@ -36,11 +36,13 @@ func (s *envSuite) TestGetenvBoolTrue(c *check.C) {
 	os.Unsetenv(key)
 
 	for _, s := range []string{
-		"1", "t", "TRUE", // etc
+		"1", "t", "TRUE",
 	} {
 		os.Setenv(key, s)
 		c.Assert(os.Getenv(key), check.Equals, s)
 		c.Check(osutil.GetenvBool(key), check.Equals, true, check.Commentf(s))
+		c.Check(osutil.GetenvBool(key, false), check.Equals, true, check.Commentf(s))
+		c.Check(osutil.GetenvBool(key, true), check.Equals, true, check.Commentf(s))
 	}
 }
 
@@ -50,10 +52,33 @@ func (s *envSuite) TestGetenvBoolFalse(c *check.C) {
 	c.Assert(osutil.GetenvBool(key), check.Equals, false)
 
 	for _, s := range []string{
-		"", "0", "f", "FALSE", // etc
+		"", "0", "f", "FALSE", "potato",
 	} {
 		os.Setenv(key, s)
 		c.Assert(os.Getenv(key), check.Equals, s)
 		c.Check(osutil.GetenvBool(key), check.Equals, false, check.Commentf(s))
+		c.Check(osutil.GetenvBool(key, false), check.Equals, false, check.Commentf(s))
+	}
+}
+
+func (s *envSuite) TestGetenvBoolFalseDefaultTrue(c *check.C) {
+	key := "__XYZZY__"
+	os.Unsetenv(key)
+	c.Assert(osutil.GetenvBool(key), check.Equals, false)
+
+	for _, s := range []string{
+		"0", "f", "FALSE",
+	} {
+		os.Setenv(key, s)
+		c.Assert(os.Getenv(key), check.Equals, s)
+		c.Check(osutil.GetenvBool(key, true), check.Equals, false, check.Commentf(s))
+	}
+
+	for _, s := range []string{
+		"", "potato", // etc
+	} {
+		os.Setenv(key, s)
+		c.Assert(os.Getenv(key), check.Equals, s)
+		c.Check(osutil.GetenvBool(key, true), check.Equals, true, check.Commentf(s))
 	}
 }