Handle multi-document YAML streams

data/data.go

@@ -123,6 +123,22 @@ func YAMLArray(in string) ([]interface{}, error) {
 	return obj, nil
 }
 
+// YAMLStream - parses a (potentially) multi-document YAML stream
+func YAMLStream(in string) ([]interface{}, error) {
+	obj := []interface{}{}
+	s := strings.NewReader(in)
+	d := yaml.NewDecoder(s)
+	for {
+		var o interface{}
+		err := d.Decode(&o)
+		if err == io.EOF {
+			break
+		}
+		obj = append(obj, o)
+	}
+	return obj, nil
+}
+
 // TOML - Unmarshal a TOML Object
 func TOML(in string) (interface{}, error) {
 	obj := make(map[string]interface{})

data/data_test.go

@@ -65,7 +65,7 @@ func TestUnmarshalArray(t *testing.T) {
 		assert.EqualValues(t, expected, actual)
 	}
 	test(JSONArray(`["foo","bar",{"baz":{"qux": true},"quux":{"42":18},"corge":{"false":"blah"}}]`))
-	test(YAMLArray(`
+	test(YAMLArray(`---
 - foo
 - bar
 - baz:
@@ -523,3 +523,22 @@ QUX='single quotes ignore $variables'
 	assert.NoError(t, err)
 	assert.EqualValues(t, expected, out)
 }
+
+func TestMultiDocYAML(t *testing.T) {
+	in := `foo: bar
+---
+baz: qux
+---
+# empty document with a comment
+`
+	expected := []interface{}{
+		map[string]interface{}{"foo": "bar"},
+		map[string]interface{}{"baz": "qux"},
+		nil,
+	}
+	ch, err := YAMLArray(in)
+	for i, out := range ch {
+		assert.NoError(t, err)
+		assert.EqualValues(t, expected[i], out)
+	}
+}

funcs/data.go

@@ -67,6 +67,11 @@ func (f *DataFuncs) YAMLArray(in interface{}) ([]interface{}, error) {
 	return data.YAMLArray(conv.ToString(in))
 }
 
+// YAMLStream -
+func (f *DataFuncs) YAMLStream(in interface{}) ([]interface{}, error) {
+	return data.YAMLStream(conv.ToString(in))
+}
+
 // TOML -
 func (f *DataFuncs) TOML(in interface{}) (interface{}, error) {
 	return data.TOML(conv.ToString(in))

internal/tests/integration/datasources_file_test.go

@@ -39,6 +39,14 @@ FOO.BAR = "values can be double-quoted, and shell\nescapes are supported"
 
 BAZ = "variable expansion: ${FOO}"
 QUX='single quotes ignore $variables'
+`,
+			"multidoc.yaml": `---
+# empty document
+---
+foo: bar
+---
+foo: baz
+...
 `,
 		}),
 		fs.WithDir("sortorder", fs.WithFiles(map[string]string{
@@ -191,4 +199,12 @@ bar`})
   "FOO.BAR": "values can be double-quoted, and shell\nescapes are supported",
   "QUX": "single quotes ignore $variables"
 }`})
+
+	result = icmd.RunCmd(icmd.Command(GomplateBin,
+		"-d=multidoc.yaml",
+		"-i", `{{ range $d := (include "multidoc" | data.YAMLStream) }}---{{"\n"}}{{ range $k, $v := $d }}{{ $k }}: {{ $v }}{{"\n"}}{{ end }}{{ end }}`,
+	), func(c *icmd.Cmd) {
+		c.Dir = s.tmpDir.Path()
+	})
+	result.Assert(c, icmd.Expected{ExitCode: 0, Out: "---\n---\nfoo: bar\n---\nfoo: baz\n"})
 }