Merge pull request #65 from illia-v/env_multiple_values

Fix providing multiple values via environment variables

1 files changed, 23 insertions, 3 deletions

diff --git a/parse.go b/parse.go
index 1416223..3c682f5 100644
--- a/parse.go
+++ b/parse.go
@@ -2,6 +2,7 @@ package arg
 
 import (
 	"encoding"
+	"encoding/csv"
 	"errors"
 	"fmt"
 	"os"
@@ -275,9 +276,28 @@ func process(specs []*spec, args []string) error {
 		}
 		if spec.env != "" {
 			if value, found := os.LookupEnv(spec.env); found {
-				err := scalar.ParseValue(spec.dest, value)
-				if err != nil {
-					return fmt.Errorf("error processing environment variable %s: %v", spec.env, err)
+				if spec.multiple {
+					// expect a CSV string in an environment
+					// variable in the case of multiple values
+					values, err := csv.NewReader(strings.NewReader(value)).Read()
+					if err != nil {
+						return fmt.Errorf(
+							"error reading a CSV string from environment variable %s with multiple values: %v",
+							spec.env,
+							err,
+						)
+					}
+					if err = setSlice(spec.dest, values, !spec.separate); err != nil {
+						return fmt.Errorf(
+							"error processing environment variable %s with multiple values: %v",
+							spec.env,
+							err,
+						)
+					}
+				} else {
+					if err := scalar.ParseValue(spec.dest, value); err != nil {
+						return fmt.Errorf("error processing environment variable %s: %v", spec.env, err)
+					}
 				}
 				spec.wasPresent = true
 			}