From 83b9cbdc3feee6279a973dc366e2dd6514358936 Mon Sep 17 00:00:00 2001
From: Elchin Gasimov <egasimov0@gmail.com>
Date: Sun, 12 Jun 2022 12:01:52 +0400
Subject: [PATCH] Issue 175: Command does not load dotenv files if some do not
 exist

---
 godotenv.go      | 16 +++++++++++++++-
 godotenv_test.go | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/godotenv.go b/godotenv.go
index 975d7bc..20e24ca 100644
--- a/godotenv.go
+++ b/godotenv.go
@@ -137,7 +137,9 @@ func Unmarshal(str string) (envMap map[string]string, err error) {
 // If you want more fine grained control over your command it's recommended
 // that you use `Load()` or `Read()` and the `os/exec` package yourself.
 func Exec(filenames []string, cmd string, cmdArgs []string) error {
-	Load(filenames...)
+
+	filteredFilenames := filterFilesNotExist(filenames)
+	Load(filteredFilenames...)
 
 	command := exec.Command(cmd, cmdArgs...)
 	command.Stdin = os.Stdin
@@ -361,3 +363,15 @@ func doubleQuoteEscape(line string) string {
 	}
 	return line
 }
+
+func filterFilesNotExist(filenames []string) []string {
+	result := make([]string, 0, len(filenames))
+	for _, fileName := range filenames {
+		if _, err := os.Stat(fileName); err != nil {
+			fmt.Fprintf(os.Stderr, "File: `%s` not found \n", fileName)
+		} else {
+			result = append(result, fileName)
+		}
+	}
+	return result
+}
diff --git a/godotenv_test.go b/godotenv_test.go
index 49f6fe0..30bae2c 100644
--- a/godotenv_test.go
+++ b/godotenv_test.go
@@ -472,3 +472,42 @@ func TestRoundtrip(t *testing.T) {
 
 	}
 }
+
+func Test_filterFilesNotExist(t *testing.T) {
+	type testCase struct {
+		description       string
+		givenFilenames    []string
+		expectedFileNames []string
+	}
+
+	testCases := []testCase{
+		testCase{
+			description: "When all files do exist, then return all",
+			givenFilenames:    []string{"fixtures/equals.env", "fixtures/exported.env"},
+			expectedFileNames: []string{"fixtures/equals.env", "fixtures/exported.env"},
+		},
+		testCase{
+			description: "When none of the files do exist, then return empty slice",
+			givenFilenames:    []string{"not-existed-file.env", "wrong-fileName.env"},
+			expectedFileNames: []string{},
+		},
+		testCase{
+			description: "When some of the files do exist, then filter and return exist files",
+			givenFilenames:    []string{"not-existed-file.env", "wrong-fileName.env", "fixtures/equals.env"},
+			expectedFileNames: []string{"fixtures/equals.env"},
+		},
+	}
+
+	for _, testCase := range testCases {
+		//when
+		actual := filterFilesNotExist(testCase.givenFilenames)
+
+		//then
+		if !reflect.DeepEqual(actual, testCase.expectedFileNames) {
+			t.Error("For", testCase.description,
+				"\n Given: ", testCase.givenFilenames,
+				"\n Expected:", testCase.expectedFileNames,
+				"\n Got", actual)
+		}
+	}
+}