implement hyphen for stdin (ref #90)

cli/cli.go

@@ -260,7 +260,9 @@ Synopsis:
 }
 
 func slurpFile(name string) (interface{}, error) {
-	iter := newSlurpInputIter(newFilesInputIter(newJSONInputIter, []string{name}))
+	iter := newSlurpInputIter(
+		newFilesInputIter(newJSONInputIter, []string{name}, nil),
+	)
 	defer iter.Close()
 	val, _ := iter.Next()
 	if err, ok := val.(error); ok {
@@ -293,7 +295,7 @@ func (cli *cli) createInputIter(args []string) (iter inputIter) {
 	if len(args) == 0 {
 		return newIter(cli.inStream, "<stdin>")
 	}
-	return newFilesInputIter(newIter, args)
+	return newFilesInputIter(newIter, args, cli.inStream)
 }
 
 func (cli *cli) process(iter inputIter, code *gojq.Code) error {

cli/inputs.go

@@ -147,13 +147,16 @@ func (i *nullInputIter) Name() string {
 type filesInputIter struct {
 	newIter func(io.Reader, string) inputIter
 	fnames  []string
+	stdin   io.Reader
 	iter    inputIter
-	file    *os.File
+	file    io.Reader
 	err     error
 }
 
-func newFilesInputIter(newIter func(io.Reader, string) inputIter, fnames []string) inputIter {
-	return &filesInputIter{newIter: newIter, fnames: fnames}
+func newFilesInputIter(
+	newIter func(io.Reader, string) inputIter, fnames []string, stdin io.Reader,
+) inputIter {
+	return &filesInputIter{newIter: newIter, fnames: fnames, stdin: stdin}
 }
 
 func (i *filesInputIter) Next() (interface{}, bool) {
@@ -168,11 +171,15 @@ func (i *filesInputIter) Next() (interface{}, bool) {
 			}
 			fname := i.fnames[0]
 			i.fnames = i.fnames[1:]
-			file, err := os.Open(fname)
-			if err != nil {
-				return err, true
+			if fname == "-" && i.stdin != nil {
+				i.file, fname = i.stdin, "<stdin>"
+			} else {
+				file, err := os.Open(fname)
+				if err != nil {
+					return err, true
+				}
+				i.file = file
 			}
-			i.file = file
 			if i.iter != nil {
 				i.iter.Close()
 			}
@@ -181,23 +188,27 @@ func (i *filesInputIter) Next() (interface{}, bool) {
 		if v, ok := i.iter.Next(); ok {
 			return v, ok
 		}
-		i.file.Close()
+		if r, ok := i.file.(io.Closer); ok && i.file != i.stdin {
+			r.Close()
+		}
 		i.file = nil
 	}
 }
 
 func (i *filesInputIter) Close() error {
 	if i.file != nil {
-		i.file.Close()
+		if r, ok := i.file.(io.Closer); ok && i.file != i.stdin {
+			r.Close()
+		}
 		i.file = nil
 		i.err = io.EOF
 	}
 	return nil
 }
 
 func (i *filesInputIter) Name() string {
-	if i.file != nil {
-		return i.file.Name()
+	if i.iter != nil {
+		return i.iter.Name()
 	}
 	return ""
 }

cli/test.yaml

@@ -4197,6 +4197,20 @@
     "testdata/1.json"
     "testdata/2.json"
 
+- name: input_filename function with hyphen for stdin
+  args:
+    - 'input_filename'
+    - '-'
+    - 'testdata/1.json'
+    - '-'
+    - 'testdata/2.json'
+    - '-'
+  input: '0'
+  expected: |
+    "<stdin>"
+    "testdata/1.json"
+    "testdata/2.json"
+
 - name: input_filename function with yaml input option
   args:
     - --yaml-input
@@ -5566,6 +5580,18 @@
       "bar"
     ]
 
+- name: yaml input option with hyphen for stdin
+  args:
+    - --yaml-input
+    - '.'
+    - '-'
+  input: |
+    foo: 1
+  expected: |
+    {
+      "foo": 1
+    }
+
 - name: yaml input option error
   args:
     - --yaml-input
@@ -5915,6 +5941,14 @@
       "bar": []
     }
 
+- name: hyphen for stdin
+  args:
+    - '.'
+    - '-'
+  input: '{}'
+  expected: |
+    {}
+
 - name: json file arguments
   args:
     - '.'
@@ -6324,6 +6358,16 @@
         .foo.bar
         ^  invalid character '.' looking for beginning of value
 
+- name: slurpfile option error
+  args:
+    - --slurpfile
+    - 'foo'
+    - '-'
+    - '{ $foo }'
+  input: 'null'
+  error: |
+    open -: no such file or directory
+
 - name: rawfile option
   args:
     - --rawfile