cmd/cue: prefer ndjson over ldjson

Per ndjson/ndjson-spec#3 in 2014,
the ldjson spec (line-delimited JSON) was renamed to ndjson
(newline-delimited JSON) and so we should use the newer extension.

We already supported loading files with the ndjson extension,
but `cue import` still only supported ldjson.

Use ndjson in all the documentation and examples,
but continue to support ldjson for backwards compatibility.

Any non-encoding tests which used ldjson files now use ndjson files
for the sake of consistency.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: Iff4a853ed5cfc34aaecece523782c4154e3e6e63
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1199412
Reviewed-by: Matthew Sackman <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

cmd/cue/cmd/help.go

@@ -518,7 +518,7 @@ var filetypeHelp = &cobra.Command{
     json        .json           JSON files.
     yaml        .yaml/.yml      YAML files.
     toml        .toml           TOML files
-    jsonl       .jsonl/.ldjson  Line-separated JSON values.
+    jsonl       .jsonl/.ndjson  Line-separated JSON values.
     jsonschema                  JSON Schema.
     openapi                     OpenAPI schema.
 	pb                          Use Protobuf mappings (e.g. json+pb)

cmd/cue/cmd/import.go

@@ -53,7 +53,7 @@ more info). This behavior can be overridden by specifying one of
 the following modes:
 
    Mode       Extensions
-   json       Look for JSON files (.json, .jsonl, .ldjson).
+   json       Look for JSON files (.json .jsonl .ndjson).
    yaml       Look for YAML files (.yaml .yml).
    toml       Look for TOML files (.toml).
    text       Look for text files (.txt).
@@ -269,7 +269,7 @@ Example:
 
 func runImport(cmd *Command, args []string) (err error) {
 	c := &config{
-		fileFilter:     `\.(json|yaml|yml|toml|jsonl|ldjson)$`,
+		fileFilter:     `\.(json|yaml|yml|toml|jsonl|ndjson|ldjson)$`,
 		interpretation: build.Auto,
 		loadCfg:        &load.Config{DataFiles: true},
 	}
@@ -289,7 +289,7 @@ func runImport(cmd *Command, args []string) (err error) {
 		case "proto":
 			c.fileFilter = `\.proto$`
 		case "json":
-			c.fileFilter = `\.(json|jsonl|ldjson)$`
+			c.fileFilter = `\.(json|jsonl|ndjson|ldjson)$`
 		case "yaml":
 			c.fileFilter = `\.(yaml|yml)$`
 		case "toml":

cmd/cue/cmd/testdata/script/embed_err.txtar

@@ -41,9 +41,9 @@ absglob: _ @embed(glob="/x/*.*", type=yaml)
 
 doublestar: _ @embed(glob="**/*.json")
 
-stream: _ @embed(file=test.ldjson)
+stream: _ @embed(file=test.ndjson)
 
-singlestream: _ @embed(file=single.ldjson)
+singlestream: _ @embed(file=single.ndjson)
 
 yamlstream: _ @embed(file=stream.yaml)
 
@@ -80,10 +80,10 @@ invalidPattern: _ @embed(glob="x[")
 
 -- test.json --
 { "x": 34 }
--- test.ldjson --
+-- test.ndjson --
 { "x": 35 }
 { "x": 36 }
--- single.ldjson --
+-- single.ndjson --
 { "x": 37 }
 -- stream.yaml --
 1

cmd/cue/cmd/testdata/script/encoding_jsonl.txtar

@@ -28,7 +28,6 @@ cmp stdout export-one.stdout
 
 # Check that `cue import` supports all filenames too,
 # both by default and when loading JSON only.
-# TODO(mvdan): ndjson is not supported here, but it should.
 # TODO(mvdan): note that `cue import --dry-run` does not work,
 # so we need to use rm and stderr checks to ensure we create the files we expect.
 
@@ -78,4 +77,5 @@ cmp stderr import.stderr
 -- import.stderr --
 importing into input-jsonl.cue
 importing into input-ldjson.cue
+importing into input-ndjson.cue
 importing into input-one.cue

cue/interpreter/embed/embed.go

@@ -54,7 +54,7 @@
 // # Limitations
 //
 // The embed interpreter currently does not support:
-// - stream values, such as .ldjson or YAML streams.
+// - stream values, such as .ndjson or YAML streams.
 // - schema-based decoding, such as needed for textproto
 //
 // # Example