cmd/cue: correctly import comments after a field key

The YAML decoder attached an inline key comment to the label,
rather than to the entire field, which caused the comment to be printed
before the colon character and cause weird formatting.

Then teach cue/format to print an inline comment on a field colon.

Fixes #3214.

Change-Id: I17e669bc6c129dde86478d604a28d07fc63f7b69
Signed-off-by: haoqixu <hq.xu0o0@gmail.com>
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1196291
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>

cmd/cue/cmd/testdata/script/import_auto.txtar

@@ -1,6 +1,18 @@
 exec cue import -o - ./openapi.yaml
 cmp stdout expect-openapi
 
+# Issue #3214
+exec cue import -o - -f ./import1.yaml
+cmp stdout expect-stdout1
+
+-- import1.yaml --
+a: # inline comment for a
+  b: "value" # inline comment for b
+-- expect-stdout1 --
+a: // inline comment for a
+{
+	b: "value" // inline comment for b
+}
 -- expect-openapi --
 // An OpenAPI file
 

cue/format/node.go

@@ -314,6 +314,7 @@ func (f *formatter) decl(decl ast.Decl) {
 		} else {
 			f.print(blank, nooverride, n.Token)
 		}
+		f.visitComments(f.current.pos)
 
 		if mem := f.inlineField(n); mem != nil {
 			switch {

internal/encoding/yaml/decode.go

@@ -401,7 +401,7 @@ outer:
 		if err != nil {
 			return err
 		}
-		d.addCommentsToNode(label, yk, 1)
+		d.addCommentsToNode(field, yk, 2)
 		field.Label = label
 
 		if mergeValues {