Fix issue parsing block comments, and always retain prefix comments f…

…or cgo imports. (#49)

* Fix "Error: an error occured while trying to parse imports: path is missing starting quotes" when parsing a file with block comments.

Fixes #48.

Note that this only handles simple cases for block comments, and does
not cover more complex cases (see FIXME in parse.go).

Signed-off-by: Charles Korn <me@charleskorn.com>

* Make block comment parsing more robust to different formatting.

Signed-off-by: Charles Korn <me@charleskorn.com>

* Add test case for multiple comments before a "C" import.

Signed-off-by: Charles Korn <me@charleskorn.com>

pkg/constants/sequences.go

@@ -1,9 +1,11 @@
 package constants
 
 const (
-	CommentFlag     = "//"
-	ImportStartFlag = "\nimport (\n"
-	ImportEndFlag   = "\n)"
+	LineCommentFlag       = "//"
+	BlockCommentStartFlag = "/*"
+	BlockCommentEndFlag   = "*/"
+	ImportStartFlag       = "\nimport (\n"
+	ImportEndFlag         = "\n)"
 
 	Blank     = " "
 	Indent    = "\t"

pkg/gci/imports/import.go

@@ -56,7 +56,7 @@ func (i ImportDef) String() string {
 func (i ImportDef) Format(cfg configuration.FormatterConfiguration) string {
 	linePrefix := constants.Indent
 	var output string
-	if cfg.NoPrefixComments == false {
+	if cfg.NoPrefixComments == false || i.QuotedPath == `"C"` {
 		for _, prefixComment := range i.PrefixComment {
 			output += linePrefix + prefixComment + constants.Linebreak
 		}

pkg/gci/internal/testdata/cgo-block-mixed-with-content.cfg.yaml

@@ -0,0 +1 @@
+no-prefixComments: true

pkg/gci/internal/testdata/cgo-block-mixed-with-content.in.go

@@ -0,0 +1,6 @@
+package main
+
+import (
+	/* #include "types.h"
+	   #include "other.h" */"C"
+)

pkg/gci/internal/testdata/cgo-block-mixed-with-content.out.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	/*
+		#include "types.h"
+		#include "other.h"
+	*/
+	"C"
+)

pkg/gci/internal/testdata/cgo-block-mixed.cfg.yaml

@@ -0,0 +1 @@
+no-prefixComments: true

pkg/gci/internal/testdata/cgo-block-mixed.in.go

@@ -0,0 +1,6 @@
+package main
+
+import (
+	/* #include "types.h"
+	 */"C"
+)

pkg/gci/internal/testdata/cgo-block-mixed.out.go

@@ -0,0 +1,8 @@
+package main
+
+import (
+	/*
+		#include "types.h"
+	*/
+	"C"
+)

pkg/gci/internal/testdata/cgo-block-prefix.cfg.yaml

@@ -0,0 +1 @@
+no-prefixComments: true

pkg/gci/internal/testdata/cgo-block-prefix.in.go

@@ -0,0 +1,5 @@
+package main
+
+import (
+	/* #include "types.h" */ "C"
+)

pkg/gci/internal/testdata/cgo-block-prefix.out.go

@@ -0,0 +1,8 @@
+package main
+
+import (
+	/*
+		#include "types.h"
+	*/
+	"C"
+)

pkg/gci/internal/testdata/cgo-block-single-line.cfg.yaml

@@ -0,0 +1 @@
+no-prefixComments: true

pkg/gci/internal/testdata/cgo-block-single-line.in.go

@@ -0,0 +1,6 @@
+package main
+
+import (
+	/* #include "types.h" */
+	"C"
+)

pkg/gci/internal/testdata/cgo-block-single-line.out.go

@@ -0,0 +1,8 @@
+package main
+
+import (
+	/*
+		#include "types.h"
+	*/
+	"C"
+)

pkg/gci/internal/testdata/cgo-block.cfg.yaml

@@ -0,0 +1 @@
+no-prefixComments: true

pkg/gci/internal/testdata/cgo-block.in.go

@@ -0,0 +1,8 @@
+package main
+
+import (
+	/*
+		#include "types.h"
+	*/
+	"C"
+)

pkg/gci/internal/testdata/cgo-block.out.go

@@ -0,0 +1,8 @@
+package main
+
+import (
+	/*
+		#include "types.h"
+	*/
+	"C"
+)

pkg/gci/internal/testdata/cgo-line.cfg.yaml

@@ -0,0 +1 @@
+no-prefixComments: true

pkg/gci/internal/testdata/cgo-line.in.go

@@ -0,0 +1,6 @@
+package main
+
+import (
+	// #include "types.h"
+	"C"
+)

pkg/gci/internal/testdata/cgo-line.out.go

@@ -0,0 +1,6 @@
+package main
+
+import (
+	// #include "types.h"
+	"C"
+)

pkg/gci/internal/testdata/cgo-multiline.cfg.yaml

@@ -0,0 +1 @@
+no-prefixComments: true

pkg/gci/internal/testdata/cgo-multiline.in.go

@@ -0,0 +1,7 @@
+package main
+
+import (
+	// #include "types.h"
+	// #include "other.h"
+	"C"
+)

pkg/gci/internal/testdata/cgo-multiline.out.go

@@ -0,0 +1,7 @@
+package main
+
+import (
+	// #include "types.h"
+	// #include "other.h"
+	"C"
+)

pkg/gci/parse.go

@@ -10,25 +10,60 @@ import (
 // Recursively parses import lines into a list of ImportDefs
 func parseToImportDefinitions(unformattedLines []string) ([]importPkg.ImportDef, error) {
 	newImport := importPkg.ImportDef{}
+	inBlockComment := false
 	for index, unformattedLine := range unformattedLines {
 		line := strings.TrimSpace(unformattedLine)
 		if line == "" {
 			//empty line --> starts a new import
 			return parseToImportDefinitions(unformattedLines[index+1:])
 		}
-		if strings.HasPrefix(line, constants.CommentFlag) {
+		if strings.HasPrefix(line, constants.LineCommentFlag) {
 			// comment line
 			newImport.PrefixComment = append(newImport.PrefixComment, line)
 			continue
 		}
+
+		if blockCommentStartsOnThisLine := strings.HasPrefix(line, constants.BlockCommentStartFlag); inBlockComment || blockCommentStartsOnThisLine {
+			blockCommentEndIndex := strings.Index(line, constants.BlockCommentEndFlag)
+			blockCommentEndsOnThisLine := blockCommentEndIndex != -1
+			contentStartsAtIndex := 0
+			contentEndsAtIndex := len(line)
+
+			if blockCommentStartsOnThisLine {
+				newImport.PrefixComment = append(newImport.PrefixComment, constants.BlockCommentStartFlag)
+				contentStartsAtIndex = len(constants.BlockCommentStartFlag)
+			}
+
+			if blockCommentEndsOnThisLine {
+				contentEndsAtIndex = blockCommentEndIndex
+			}
+
+			if content := strings.TrimSpace(line[contentStartsAtIndex:contentEndsAtIndex]); content != "" {
+				newImport.PrefixComment = append(newImport.PrefixComment, "\t"+content)
+			}
+
+			inBlockComment = !blockCommentEndsOnThisLine
+
+			if !blockCommentEndsOnThisLine {
+				continue
+			}
+
+			newImport.PrefixComment = append(newImport.PrefixComment, constants.BlockCommentEndFlag)
+			line = line[blockCommentEndIndex+len(constants.BlockCommentEndFlag):]
+
+			if line == "" {
+				continue
+			}
+		}
+
 		// split inline comment from import
-		importSegments := strings.SplitN(line, constants.CommentFlag, 2)
+		importSegments := strings.SplitN(line, constants.LineCommentFlag, 2)
 		switch len(importSegments) {
 		case 1:
 			// no inline comment
 		case 2:
 			// inline comment present
-			newImport.InlineComment = constants.CommentFlag + importSegments[1]
+			newImport.InlineComment = constants.LineCommentFlag + importSegments[1]
 		default:
 			return nil, InvalidImportSplitError{importSegments}
 		}