trim trailing newlines

PiperOrigin-RevId: 523324423
protocolbuffers · Apr 11, 2023 · 7962e19 · 7962e19
1 parent 3462fbc
commit 7962e19
Show file tree

Hide file tree

Showing 2 changed files with 45 additions and 6 deletions.
diff --git a/parser/parser.go b/parser/parser.go
@@ -1337,13 +1337,25 @@ func DebugFormat(nodes []*ast.Node, depth int) string {
 func Pretty(nodes []*ast.Node, depth int) string {
 	var result strings.Builder
 	formatter{&result}.writeNodes(removeDeleted(nodes), depth, false /* isSameLine */, false /* asListItems */)
-	return result.String()
+
+	// Trim excess trailing newlines.
+	res := result.String()
+	if strings.HasSuffix(res, "\n\n") {
+		return res[:len(res)-1]
+	}
+	return res
 }
 
 func out(nodes []*ast.Node) []byte {
 	var result bytes.Buffer
 	formatter{&result}.writeNodes(removeDeleted(nodes), 0, false /* isSameLine */, false /* asListItems */)
-	return result.Bytes()
+
+	// Trim excess trailing newlines.
+	res := result.Bytes()
+	if bytes.HasSuffix(res, []byte("\n\n")) {
+		return res[:len(res)-1]
+	}
+	return res
 }
 
 // UnsortedFieldCollector collects UnsortedFields during parsing.

diff --git a/parser/parser_test.go b/parser/parser_test.go
@@ -335,7 +335,6 @@ presubmit: {
   review_notify: "address"  # review same line comment 2
 
 }
-
 `}, {
 		name: "empty children",
 		in: `
@@ -359,7 +358,6 @@ presubmit: {
 # presubmit comment 2
 presubmit: {
 }
-
 `}, {
 		name: "list notation with []",
 		in: `
@@ -605,7 +603,6 @@ tricorder: {
 options:
   "first line"  # first comment
   "second line"  # second comment
-
 `}, {
 		name: "all kinds of inline comments",
 		in: `# presubmit pre comment 1
@@ -826,7 +823,6 @@ check_tests: {
 `,
 		out: `presubmit {
 }
-
 `}, {
 		name: "template directive",
 		in: `[ext]: {
@@ -2355,6 +2351,37 @@ foo {
 foo: "\"bar\""`,
 		out: `# txtpbfmt: smartquotes
 foo: '"bar"'
+`,
+	}, {
+		name: "blank lines",
+		in: `
+
+
+# comment 0
+# comment 1
+
+
+
+# comment 2
+
+# comment 3
+blah {
+
+
+
+}
+
+
+`,
+		out: `# comment 0
+# comment 1
+
+# comment 2
+
+# comment 3
+blah {
+
+}
 `,
 	},
 	}