force multiline function signatures to separate the body

closes #73

README.md

@@ -40,6 +40,7 @@ No empty lines at the beginning or end of a function
 
 ```
 func foo() {
+
  println("bar")
 
 }
@@ -53,6 +54,28 @@ func foo() {
 
 </details>
 
+Functions using an empty line for readability should use a `) {` line instead
+
+<details><summary><i>example</i></summary>
+
+```
+func foo(s string,
+ i int) {
+
+ println("bar")
+}
+```
+
+```
+func foo(s string,
+ i int,
+) {
+ println("bar")
+}
+```
+
+</details>
+
 No empty lines around a lone statement (or comment) in a block
 
 <details><summary><i>example</i></summary>

format/format.go

@@ -542,12 +542,22 @@ func (f *fumpter) applyPre(c *astutil.Cursor) {
  f.Position(sign.Results.Closing).Column == 1 &&
  f.Line(sign.Results.Closing) == endLine
 
- if f.Line(sign.Pos()) != endLine &&
- // param/result closing is not the 1st char of the left bracket line
- !(paramClosingIsFirstCharOnEndLine || resultClosingIsFirstCharOnEndLine) {
+ endLineIsIndented := !(paramClosingIsFirstCharOnEndLine || resultClosingIsFirstCharOnEndLine)
+
+ if f.Line(sign.Pos()) != endLine && endLineIsIndented {
+ // is there an empty line?
+ isThereAnEmptyLine := endLine+1 != f.Line(bodyPos)
+
  // The body is preceded by a multi-line function
- // signature, and the empty line helps readability.
- return
+ // signature, we move the `) {` to avoid the empty line.
+ switch {
+ case isThereAnEmptyLine && sign.Results != nil && !resultClosingIsFirstCharOnEndLine:
+ sign.Results.Closing += 1
+ f.addNewline(sign.Results.Closing)
+ case isThereAnEmptyLine && sign.Params != nil && !paramClosingIsFirstCharOnEndLine:
+ sign.Params.Closing += 1
+ f.addNewline(sign.Params.Closing)
+ }
  }
  }
 

testdata/scripts/func-newlines.txt

@@ -230,6 +230,25 @@ func f2(
 
  return "", nil
 }
+
+func multilineResultsMultipleEmptyLines() (p1 string,
+ p2 string) {
+
+
+ println("body")
+
+}
+
+func multilineParamsWithoutEmptyLine(p1 string,
+ p2 string) {
+ println("body")
+}
+
+func multilineParamsWithoutEmptyLineWithComment(p1 string,
+ p2 string) {
+ // comment
+ println("body")
+}
 -- foo.go.golden --
 package p
 
@@ -253,8 +272,8 @@ func _() {
 }
 
 func multilineParams(p1 string,
- p2 string) {
-
+ p2 string,
+) {
  println("body")
 }
 
@@ -380,8 +399,8 @@ func multilineParamsOneParamReturningMultiLineValues(
 }
 
 func multilineResults() (p1 string,
- p2 string) {
-
+ p2 string,
+) {
  println("body")
 }
 
@@ -398,8 +417,8 @@ func multilineNoFields() {
 func f(
  foo int,
  bar string,
- /* baz */) {
-
+ /* baz */
+) {
  body()
 }
 
@@ -409,7 +428,24 @@ func f2(
 ) (
  string,
  error,
- /* baz */) {
-
+ /* baz */
+) {
  return "", nil
 }
+
+func multilineResultsMultipleEmptyLines() (p1 string,
+ p2 string,
+) {
+ println("body")
+}
+
+func multilineParamsWithoutEmptyLine(p1 string,
+ p2 string) {
+ println("body")
+}
+
+func multilineParamsWithoutEmptyLineWithComment(p1 string,
+ p2 string) {
+ // comment
+ println("body")
+}