Add missing newlines and add flag --no-trailing-newline to not do that

cmd/jsonnet/cmd.go

@@ -51,6 +51,7 @@ func usage(o io.Writer) {
 	fmt.Fprintln(o, "                             files")
 	fmt.Fprintln(o, "  -y / --yaml-stream         Write output as a YAML stream of JSON documents")
 	fmt.Fprintln(o, "  -S / --string              Expect a string, manifest as plain text")
+	fmt.Fprintln(o, "  --no-trailing-newline      Do not add a trailing newline to the output")
 	fmt.Fprintln(o, "  -s / --max-stack <n>       Number of allowed stack frames")
 	fmt.Fprintln(o, "  -t / --max-trace <n>       Max length of stack trace before cropping")
 	fmt.Fprintln(o, "  --version                  Print version")
@@ -256,13 +257,21 @@ func processArgs(givenArgs []string, config *config, vm *jsonnet.VM) (processArg
 			config.evalStream = true
 		} else if arg == "-S" || arg == "--string" {
 			vm.StringOutput = true
+		} else if arg == "--no-trailing-newline" {
+			vm.OutputNewline = false
 		} else if len(arg) > 1 && arg[0] == '-' {
 			return processArgsStatusFailure, fmt.Errorf("unrecognized argument: %s", arg)
 		} else {
 			remainingArgs = append(remainingArgs, arg)
 		}
 	}
 
+	// --no-trailing-newline is meaningless when used with --yaml-stream
+	// so we explicitly reject it to prevent people from relying on it.
+	if config.evalStream && !vm.OutputNewline {
+		return processArgsStatusFailure, fmt.Errorf("cannot use --no-trailing-newline with --yaml-stream")
+	}
+
 	want := "filename"
 	if config.filenameIsCode {
 		want = "code"

interpreter.go

@@ -902,7 +902,7 @@ func (i *interpreter) manifestString(buf *bytes.Buffer, v value) error {
 	}
 }
 
-func (i *interpreter) manifestAndSerializeMulti(v value, stringOutputMode bool) (r map[string]string, err error) {
+func (i *interpreter) manifestAndSerializeMulti(v value, stringOutputMode bool, outputNewline bool) (r map[string]string, err error) {
 	r = make(map[string]string)
 	json, err := i.manifestJSON(v)
 	if err != nil {
@@ -911,21 +911,23 @@ func (i *interpreter) manifestAndSerializeMulti(v value, stringOutputMode bool)
 	switch json := json.(type) {
 	case map[string]interface{}:
 		for filename, fileJSON := range json {
+			var buf bytes.Buffer
 			if stringOutputMode {
 				switch val := fileJSON.(type) {
 				case string:
-					r[filename] = val
+					buf.WriteString(val)
 				default:
 					msg := fmt.Sprintf("multi mode: top-level object's key %s has a value of type %T, "+
 						"should be a string", filename, val)
 					return r, makeRuntimeError(msg, i.getCurrentStackTrace())
 				}
 			} else {
-				var buf bytes.Buffer
 				serializeJSON(fileJSON, true, "", &buf)
+			}
+			if outputNewline {
 				buf.WriteString("\n")
-				r[filename] = buf.String()
 			}
+			r[filename] = buf.String()
 		}
 	default:
 		msg := fmt.Sprintf("multi mode: top-level object was a %s, "+
@@ -1350,15 +1352,7 @@ func evaluateAux(i *interpreter, node ast.Node, tla vmExtMap) (value, error) {
 	return result, nil
 }
 
-// TODO(sbarzowski) this function takes far too many arguments - build interpreter in vm instead
-func evaluate(node ast.Node, ext vmExtMap, tla vmExtMap, nativeFuncs map[string]*NativeFunction,
-	maxStack int, ic *importCache, traceOut io.Writer, stringOutputMode bool, evalHook EvalHook) (string, error) {
-
-	i, err := buildInterpreter(ext, nativeFuncs, maxStack, ic, traceOut, evalHook)
-	if err != nil {
-		return "", err
-	}
-
+func evaluate(i *interpreter, node ast.Node, tla vmExtMap, stringOutputMode bool, outputNewline bool) (string, error) {
 	result, err := evaluateAux(i, node, tla)
 	if err != nil {
 		return "", err
@@ -1375,39 +1369,25 @@ func evaluate(node ast.Node, ext vmExtMap, tla vmExtMap, nativeFuncs map[string]
 	if err != nil {
 		return "", err
 	}
-	buf.WriteString("\n")
+	if outputNewline {
+		buf.WriteString("\n")
+	}
 	return buf.String(), nil
 }
 
-// TODO(sbarzowski) this function takes far too many arguments - build interpreter in vm instead
-func evaluateMulti(node ast.Node, ext vmExtMap, tla vmExtMap, nativeFuncs map[string]*NativeFunction,
-	maxStack int, ic *importCache, traceOut io.Writer, stringOutputMode bool, evalHook EvalHook) (map[string]string, error) {
-
-	i, err := buildInterpreter(ext, nativeFuncs, maxStack, ic, traceOut, evalHook)
-	if err != nil {
-		return nil, err
-	}
-
+func evaluateMulti(i *interpreter, node ast.Node, tla vmExtMap, stringOutputMode bool, outputNewline bool) (map[string]string, error) {
 	result, err := evaluateAux(i, node, tla)
 	if err != nil {
 		return nil, err
 	}
 
 	i.stack.setCurrentTrace(manifestationTrace())
-	manifested, err := i.manifestAndSerializeMulti(result, stringOutputMode)
+	manifested, err := i.manifestAndSerializeMulti(result, stringOutputMode, outputNewline)
 	i.stack.clearCurrentTrace()
 	return manifested, err
 }
 
-// TODO(sbarzowski) this function takes far too many arguments - build interpreter in vm instead
-func evaluateStream(node ast.Node, ext vmExtMap, tla vmExtMap, nativeFuncs map[string]*NativeFunction,
-	maxStack int, ic *importCache, traceOut io.Writer, evalHook EvalHook) ([]string, error) {
-
-	i, err := buildInterpreter(ext, nativeFuncs, maxStack, ic, traceOut, evalHook)
-	if err != nil {
-		return nil, err
-	}
-
+func evaluateStream(i *interpreter, node ast.Node, tla vmExtMap) ([]string, error) {
 	result, err := evaluateAux(i, node, tla)
 	if err != nil {
 		return nil, err

main_test.go

@@ -108,6 +108,7 @@ type jsonnetInput struct {
 	input            []byte
 	eKind            evalKind
 	stringOutputMode bool
+	noNewline        bool // not nice to have a negative flag, but it gives the more relevant default
 	extVars          map[string]string
 	extCode          map[string]string
 }
@@ -134,6 +135,7 @@ func runInternalJsonnet(i jsonnetInput) jsonnetResult {
 	errFormatter := termErrorFormatter{pretty: true, maxStackTraceSize: 9}
 
 	vm.StringOutput = i.stringOutputMode
+	vm.OutputNewline = !i.noNewline
 	for name, value := range i.extVars {
 		vm.ExtVar(name, value)
 	}
@@ -336,6 +338,7 @@ func runTest(t *testing.T, test *mainTest) {
 		input:            input,
 		eKind:            eKind,
 		stringOutputMode: strings.HasSuffix(test.golden, "_string_output.golden"),
+		noNewline:        strings.Contains(test.golden, "_no_newline"),
 		extVars:          test.meta.extVars,
 		extCode:          test.meta.extCode,
 	})

testdata/cpp-tests-override/help.golden.stdout

@@ -0,0 +1,55 @@
+Jsonnet commandline interpreter (Go implementation) v0.21.0
+
+jsonnet {<option>} <filename>
+
+Available options:
+  -h / --help                This message
+  -e / --exec                Treat filename as code
+  -J / --jpath <dir>         Specify an additional library search dir
+                             (right-most wins)
+  -o / --output-file <file>  Write to the output file rather than stdout
+  -m / --multi <dir>         Write multiple files to the directory, list files
+                             on stdout
+  -c / --create-output-dirs  Automatically creates all parent directories for
+                             files
+  -y / --yaml-stream         Write output as a YAML stream of JSON documents
+  -S / --string              Expect a string, manifest as plain text
+  --no-trailing-newline      Do not add a trailing newline to the output
+  -s / --max-stack <n>       Number of allowed stack frames
+  -t / --max-trace <n>       Max length of stack trace before cropping
+  --version                  Print version
+
+Available options for specifying values of 'external' variables:
+  Provide the value as a string:
+  -V / --ext-str <var>[=<val>]      If <val> is omitted, get from environment
+                                    var <var>
+       --ext-str-file <var>=<file>  Read the string from the file
+  Provide a value as Jsonnet code:
+  --ext-code <var>[=<code>]         If <code> is omitted, get from environment
+                                    var <var>
+  --ext-code-file <var>=<file>      Read the code from the file
+
+Available options for specifying values of 'top-level arguments':
+  Provide the value as a string:
+  -A / --tla-str <var>[=<val>]      If <val> is omitted, get from environment
+                                    var <var>
+       --tla-str-file <var>=<file>  Read the string from the file
+  Provide a value as Jsonnet code:
+  --tla-code <var>[=<code>]         If <code> is omitted, get from environment
+                                    var <var>
+  --tla-code-file <var>=<file>      Read the code from the file
+
+Environment variables:
+  JSONNET_PATH is a colon (semicolon on Windows) separated list of directories
+  added in reverse order before the paths specified by --jpath (i.e. left-most
+  wins). E.g. these are equivalent:
+    JSONNET_PATH=a:b jsonnet -J c -J d
+    JSONNET_PATH=d:c:a:b jsonnet
+    jsonnet -J b -J a -J c -J d
+
+In all cases:
+  <filename> can be - (stdin)
+  Multichar options are expanded e.g. -abc becomes -a -b -c.
+  The -- option suppresses option processing for subsequent arguments.
+  Note that since filenames and jsonnet programs can begin with -, it is
+  advised to use -- if the argument is unknown, e.g. jsonnet -- "$FILENAME".

testdata/cpp-tests-override/no_args.golden.stderr

@@ -0,0 +1,57 @@
+ERROR: must give filename
+
+Jsonnet commandline interpreter (Go implementation) v0.21.0
+
+jsonnet {<option>} <filename>
+
+Available options:
+  -h / --help                This message
+  -e / --exec                Treat filename as code
+  -J / --jpath <dir>         Specify an additional library search dir
+                             (right-most wins)
+  -o / --output-file <file>  Write to the output file rather than stdout
+  -m / --multi <dir>         Write multiple files to the directory, list files
+                             on stdout
+  -c / --create-output-dirs  Automatically creates all parent directories for
+                             files
+  -y / --yaml-stream         Write output as a YAML stream of JSON documents
+  -S / --string              Expect a string, manifest as plain text
+  --no-trailing-newline      Do not add a trailing newline to the output
+  -s / --max-stack <n>       Number of allowed stack frames
+  -t / --max-trace <n>       Max length of stack trace before cropping
+  --version                  Print version
+
+Available options for specifying values of 'external' variables:
+  Provide the value as a string:
+  -V / --ext-str <var>[=<val>]      If <val> is omitted, get from environment
+                                    var <var>
+       --ext-str-file <var>=<file>  Read the string from the file
+  Provide a value as Jsonnet code:
+  --ext-code <var>[=<code>]         If <code> is omitted, get from environment
+                                    var <var>
+  --ext-code-file <var>=<file>      Read the code from the file
+
+Available options for specifying values of 'top-level arguments':
+  Provide the value as a string:
+  -A / --tla-str <var>[=<val>]      If <val> is omitted, get from environment
+                                    var <var>
+       --tla-str-file <var>=<file>  Read the string from the file
+  Provide a value as Jsonnet code:
+  --tla-code <var>[=<code>]         If <code> is omitted, get from environment
+                                    var <var>
+  --tla-code-file <var>=<file>      Read the code from the file
+
+Environment variables:
+  JSONNET_PATH is a colon (semicolon on Windows) separated list of directories
+  added in reverse order before the paths specified by --jpath (i.e. left-most
+  wins). E.g. these are equivalent:
+    JSONNET_PATH=a:b jsonnet -J c -J d
+    JSONNET_PATH=d:c:a:b jsonnet
+    jsonnet -J b -J a -J c -J d
+
+In all cases:
+  <filename> can be - (stdin)
+  Multichar options are expanded e.g. -abc becomes -a -b -c.
+  The -- option suppresses option processing for subsequent arguments.
+  Note that since filenames and jsonnet programs can begin with -, it is
+  advised to use -- if the argument is unknown, e.g. jsonnet -- "$FILENAME".

testdata/multi_no_newline.golden/bar.json

@@ -0,0 +1,7 @@
+{
+   "foo": {
+      "bar": {
+         "baz": "yes"
+      }
+   }
+}

testdata/multi_no_newline.golden/foo.json

@@ -0,0 +1,4 @@
+{
+   "baq": "27",
+   "baz": 3
+}

testdata/multi_no_newline.jsonnet

@@ -0,0 +1,13 @@
+{
+  "foo.json": {
+    baz: 3,
+    baq: "27",
+  },
+  "bar.json": {
+    foo: {
+      bar: {
+        baz: "yes",
+      },
+    },
+  },
+}

testdata/multi_no_newline_string_output.golden/bar.txt

@@ -0,0 +1 @@
+bar

testdata/multi_no_newline_string_output.golden/foo.txt

@@ -0,0 +1 @@
+foo.

testdata/multi_no_newline_string_output.jsonnet

@@ -0,0 +1,6 @@
+{
+    "foo.txt": |||-
+        foo.
+    |||,
+    "bar.txt": "bar",
+}

testdata/multi_string_output.golden/bar.txt

@@ -1 +1 @@
-bar
+bar

testdata/multi_string_output.jsonnet

@@ -1,5 +1,5 @@
 {
-    "foo.txt": |||
+    "foo.txt": |||-
         foo.
     |||,
     "bar.txt": "bar",

testdata/object_no_newline.golden

@@ -0,0 +1,3 @@
+{
+   "x": 2
+}

testdata/object_no_newline.jsonnet

@@ -0,0 +1 @@
+{"x": 1+1}