Allow multiple files with no expression

acceptance_tests/basic.sh

@@ -13,7 +13,56 @@ testBasicEvalRoundTrip() {
 testBasicPipeWithDot() {
   ./yq -n ".a = 123" > test.yml
   X=$(cat test.yml | ./yq '.')
-  assertEquals 123 "$X"
+  assertEquals "a: 123" "$X"
+}
+
+testBasicAllFiles() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(./yq test.yml test2.yml)
+  Y=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicEvalAllAllFiles() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(./yq ea test.yml test2.yml)
+  Y=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+
+testBasicStdInWithFiles() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq - test2.yml)
+  Y=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicEvalAllStdInWithFiles() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq ea - test2.yml)
+  Y=$(./yq e '.' test.yml test2.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicStdInWithFilesReverse() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq test2.yml -)
+  Y=$(./yq e '.' test2.yml test.yml)
+  assertEquals "$Y" "$X"
+}
+
+testBasicEvalAllStdInWithFilesReverse() {
+  ./yq -n ".a = 123" > test.yml
+  ./yq -n ".a = 124" > test2.yml
+  X=$(cat test.yml | ./yq ea test2.yml -)
+  Y=$(./yq e '.' test2.yml test.yml)
+  assertEquals "$Y" "$X"
 }
 
 testBasicEvalRoundTripNoEval() {

cmd/evaluate_all_command.go

@@ -144,7 +144,13 @@ func evaluateAll(cmd *cobra.Command, args []string) (cmdError error) {
 			err = allAtOnceEvaluator.EvaluateFiles(processExpression(""), []string{args[0]}, printer, leadingContentPreProcessing, decoder)
 		}
 	default:
-		err = allAtOnceEvaluator.EvaluateFiles(processExpression(args[0]), args[1:], printer, leadingContentPreProcessing, decoder)
+		// the first argument is either an expression - or a file.
+		if args[0] == "-" || maybeFile(args[0]) {
+			err = allAtOnceEvaluator.EvaluateFiles(processExpression(""), args, printer, leadingContentPreProcessing, decoder)
+		} else {
+			// first argument is an expression, the rest are files.
+			err = allAtOnceEvaluator.EvaluateFiles(processExpression(args[0]), args[1:], printer, leadingContentPreProcessing, decoder)
+		}
 	}
 
 	completedSuccessfully = err == nil

cmd/evalute_sequence_command.go

@@ -162,7 +162,15 @@ func evaluateSequence(cmd *cobra.Command, args []string) (cmdError error) {
 			err = streamEvaluator.EvaluateFiles(processExpression(""), []string{args[0]}, printer, leadingContentPreProcessing, decoder)
 		}
 	default:
-		err = streamEvaluator.EvaluateFiles(processExpression(args[0]), args[1:], printer, leadingContentPreProcessing, decoder)
+		// the first argument is either an expression - or a file.
+		if args[0] == "-" || maybeFile(args[0]) {
+			// its a file, there is no expression given
+			err = streamEvaluator.EvaluateFiles(processExpression(""), args, printer, leadingContentPreProcessing, decoder)
+		} else {
+			// first argument is an expression, the rest are files.
+			err = streamEvaluator.EvaluateFiles(processExpression(args[0]), args[1:], printer, leadingContentPreProcessing, decoder)
+		}
+
 	}
 	completedSuccessfully = err == nil