encoding/yaml: fix bug where an empty document is not treated as null
Change-Id: Ibb763b5e44d6c80d569db8df863d79631d0d2935
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/6561
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/encoding/yaml/yaml.go b/encoding/yaml/yaml.go
index 80c19b9..0787077 100644
--- a/encoding/yaml/yaml.go
+++ b/encoding/yaml/yaml.go
@@ -37,11 +37,14 @@
}
for {
expr, err := d.Decode()
- if err == io.EOF {
- break
- }
if err != nil {
- return nil, err
+ if err != io.EOF {
+ return nil, err
+ }
+ if expr != nil {
+ a = append(a, expr)
+ }
+ break
}
a = append(a, expr)
}
diff --git a/encoding/yaml/yaml_test.go b/encoding/yaml/yaml_test.go
index a9ce43d..304b488 100644
--- a/encoding/yaml/yaml_test.go
+++ b/encoding/yaml/yaml_test.go
@@ -27,9 +27,19 @@
testCases := []struct {
name string
yaml string
+ yamlOut string
want string
isStream bool
}{{
+ name: "empty",
+ yaml: "",
+ yamlOut: "null",
+ want: "null",
+ }, {
+ name: "empty stream",
+ want: "null",
+ isStream: true,
+ }, {
name: "string literal",
yaml: `foo`,
want: `"foo"`,
@@ -54,7 +64,37 @@
}]`,
isStream: true,
}, {
- name: "emtpy",
+ name: "stream with null",
+ yaml: `
+---
+a: foo
+---
+---
+b: bar
+c: baz
+---
+`,
+ // Not sure if a leading document separator should be gobbled, but the
+ // YAML parser seems to think so. This could have something to do with
+ // the fact that the document separator is really an "end of directives"
+ // marker, while ... means "end of document". YAML is hard!
+ yamlOut: `a: foo
+---
+null
+---
+b: bar
+c: baz
+---
+null
+`,
+ // TODO(bug): seems like bug in yaml parser. Try moving to yaml.v3,
+ // or validate that this is indeed a correct interpretation.
+ want: `[{
+ a: "foo"
+}, null, {
+ b: "bar"
+ c: "baz"
+}, null]`,
isStream: true,
}}
r := &cue.Runtime{}
@@ -66,7 +106,7 @@
}
b, _ := format.Node(f)
if got := strings.TrimSpace(string(b)); got != tc.want {
- t.Errorf("got %q; want %q", got, tc.want)
+ t.Errorf("Extract:\ngot %q\nwant %q", got, tc.want)
}
inst, err := Decode(r, tc.name, tc.yaml)
@@ -79,7 +119,12 @@
}
b, _ = format.Node(n)
if got := strings.TrimSpace(string(b)); got != tc.want {
- t.Errorf("got %q; want %q", got, tc.want)
+ t.Errorf("Decode:\ngot %q\nwant %q", got, tc.want)
+ }
+
+ yamlOut := tc.yaml
+ if tc.yamlOut != "" {
+ yamlOut = tc.yamlOut
}
inst, _ = r.Compile(tc.name, tc.want)
@@ -88,8 +133,8 @@
if err != nil {
t.Error(err)
}
- if got := strings.TrimSpace(string(b)); got != tc.yaml {
- t.Errorf("got %q; want %q", got, tc.yaml)
+ if got := strings.TrimSpace(string(b)); got != yamlOut {
+ t.Errorf("Encode:\ngot %q\nwant %q", got, yamlOut)
}
} else {
iter, _ := inst.Value().List()
@@ -97,8 +142,8 @@
if err != nil {
t.Error(err)
}
- if got := string(b); got != tc.yaml {
- t.Errorf("got %q; want %q", got, tc.yaml)
+ if got := string(b); got != yamlOut {
+ t.Errorf("EncodeStream:\ngot %q\nwant %q", got, yamlOut)
}
}
})
diff --git a/internal/third_party/yaml/yaml.go b/internal/third_party/yaml/yaml.go
index 20ef3a1..5177614 100644
--- a/internal/third_party/yaml/yaml.go
+++ b/internal/third_party/yaml/yaml.go
@@ -86,8 +86,9 @@
// A Decorder reads and decodes YAML values from an input stream.
type Decoder struct {
- strict bool
- parser *parser
+ strict bool
+ firstDone bool
+ parser *parser
}
// NewDecoder returns a new decoder that reads from r.
@@ -113,8 +114,12 @@
defer handleErr(&err)
node := dec.parser.parse()
if node == nil {
- return nil, io.EOF
+ if !dec.firstDone {
+ expr = ast.NewNull()
+ }
+ return expr, io.EOF
}
+ dec.firstDone = true
expr = d.unmarshal(node)
if len(d.terrors) > 0 {
return nil, &TypeError{d.terrors}
