Merge pull request #266 from mrVanboy/ib/fix-gomod-comments

parser: Fix go.mod endline comments parsing

parser/modulepath.go

@@ -0,0 +1,82 @@
+package parser
+
+import (
+	"bytes"
+	"strconv"
+)
+
+// Content of this file was copied from the package golang.org/x/mod/modfile
+// https://github.com/golang/mod/blob/v0.2.0/modfile/read.go#L877
+// Under the BSD-3-Clause licence:
+// golang.org/x/mod@v0.2.0/LICENSE
+/*
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+var (
+	slashSlash = []byte("//")
+	moduleStr  = []byte("module")
+)
+
+// modulePath returns the module path from the gomod file text.
+// If it cannot find a module path, it returns an empty string.
+// It is tolerant of unrelated problems in the go.mod file.
+func modulePath(mod []byte) string {
+	for len(mod) > 0 {
+		line := mod
+		mod = nil
+		if i := bytes.IndexByte(line, '\n'); i >= 0 {
+			line, mod = line[:i], line[i+1:]
+		}
+		if i := bytes.Index(line, slashSlash); i >= 0 {
+			line = line[:i]
+		}
+		line = bytes.TrimSpace(line)
+		if !bytes.HasPrefix(line, moduleStr) {
+			continue
+		}
+		line = line[len(moduleStr):]
+		n := len(line)
+		line = bytes.TrimSpace(line)
+		if len(line) == n || len(line) == 0 {
+			continue
+		}
+
+		if line[0] == '"' || line[0] == '`' {
+			p, err := strconv.Unquote(string(line))
+			if err != nil {
+				return "" // malformed quoted string or multiline module path
+			}
+			return p
+		}
+
+		return string(line)
+	}
+	return "" // missing module path
+}

parser/pkgpath.go

@@ -8,7 +8,6 @@ import (
 	"os/exec"
 	"path"
 	"path/filepath"
-	"strconv"
 	"strings"
 	"sync"
 )
@@ -91,7 +90,6 @@ func getPkgPathFromGoMod(fname string, isDir bool, goModPath string) (string, er
 }
 
 var (
-	modulePrefix          = []byte("\nmodule ")
 	pkgPathFromGoModCache = make(map[string]string)
 )
 
@@ -109,36 +107,7 @@ func getModulePath(goModPath string) string {
 	if err != nil {
 		return ""
 	}
-	var i int
-	if bytes.HasPrefix(data, modulePrefix[1:]) {
-		i = 0
-	} else {
-		i = bytes.Index(data, modulePrefix)
-		if i < 0 {
-			return ""
-		}
-		i++
-	}
-	line := data[i:]
-
-	// Cut line at \n, drop trailing \r if present.
-	if j := bytes.IndexByte(line, '\n'); j >= 0 {
-		line = line[:j]
-	}
-	if line[len(line)-1] == '\r' {
-		line = line[:len(line)-1]
-	}
-	line = line[len("module "):]
-
-	// If quoted, unquote.
-	pkgPath = strings.TrimSpace(string(line))
-	if pkgPath != "" && pkgPath[0] == '"' {
-		s, err := strconv.Unquote(pkgPath)
-		if err != nil {
-			return ""
-		}
-		pkgPath = s
-	}
+	pkgPath = modulePath(data)
 	return pkgPath
 }
 

parser/pkgpath_test.go

@@ -0,0 +1,39 @@
+package parser
+
+import "testing"
+
+func Test_getModulePath(t *testing.T) {
+	tests := map[string]struct {
+		goModPath string
+		want      string
+	}{
+		"valid go.mod without comments and deps": {
+			goModPath: "./testdata/default.go.mod",
+			want:      "example.com/user/project",
+		},
+		"valid go.mod with comments and without deps": {
+			goModPath: "./testdata/comments.go.mod",
+			want:      "example.com/user/project",
+		},
+		"valid go.mod with comments and deps": {
+			goModPath: "./testdata/comments_deps.go.mod",
+			want:      "example.com/user/project",
+		},
+		"actual easyjson go.mod": {
+			goModPath: "../go.mod",
+			want:      "github.com/mailru/easyjson",
+		},
+		"invalid go.mod with missing module": {
+			goModPath: "./testdata/missing_module.go",
+			want:      "",
+		},
+	}
+	for name := range tests {
+		tt := tests[name]
+		t.Run(name, func(t *testing.T) {
+			if got := getModulePath(tt.goModPath); got != tt.want {
+				t.Errorf("getModulePath() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

parser/testdata/comments.go.mod

@@ -0,0 +1,4 @@
+// first-line comment which should bresk anything
+module example.com/user/project // end-line comment which should not break anything
+
+go 1.13

parser/testdata/comments_deps.go.mod

@@ -0,0 +1,8 @@
+// first-line comment which should bresk anything
+module example.com/user/project // end-line comment which should not break anything
+
+go 1.13
+
+require (
+	github.com/mailru/easyjson v0.7.0
+)

parser/testdata/default.go.mod

@@ -0,0 +1,3 @@
+module example.com/user/project
+
+go 1.13

parser/testdata/missing_module.go.mod

@@ -0,0 +1,6 @@
+
+go 1.13
+
+require (
+	github.com/mailru/easyjson v0.7.0
+)