github.com/google/osv-scalibr@v0.4.1/enricher/govulncheck/source/internal/url/url.go (about)

     1  // Copyright 2025 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Derived from https://github.com/golang/go/blob/7c2b69080a0b9e35174cc9c93497b6e7176f8275/src/cmd/go/internal/web/url.go
    16  // TODO(golang.org/issue/32456): If accepted, move these functions into the
    17  // net/url package.
    18  //
    19  // Copyright 2023 The Go Authors. All rights reserved.
    20  // Use of this source code is governed by a BSD-style
    21  // license that can be found in the LICENSE file.
    22  
    23  // Package url creates a url.URL object that is compatible with govulncheck
    24  package url
    25  
    26  import (
    27  	"errors"
    28  	"net/url"
    29  	"path/filepath"
    30  	"strings"
    31  )
    32  
    33  // ErrNotAbsolute is returned when the input path is not absolute.
    34  var ErrNotAbsolute = errors.New("path is not absolute")
    35  
    36  // FromFilePath creates a url.URL object from a file path.
    37  func FromFilePath(path string) (*url.URL, error) {
    38  	if !filepath.IsAbs(path) {
    39  		return nil, ErrNotAbsolute
    40  	}
    41  
    42  	// If path has a Windows volume name, convert the volume to a host and prefix
    43  	// per https://blogs.msdn.microsoft.com/ie/2006/12/06/file-uris-in-windows/.
    44  	if vol := filepath.VolumeName(path); vol != "" {
    45  		if strings.HasPrefix(vol, `\\`) {
    46  			path = filepath.ToSlash(path[2:])
    47  			i := strings.IndexByte(path, '/')
    48  
    49  			if i < 0 {
    50  				// A degenerate case.
    51  				// \\host.example.com (without a share name)
    52  				// becomes
    53  				// file://host.example.com/
    54  				return &url.URL{
    55  					Scheme: "file",
    56  					Host:   path,
    57  					Path:   "/",
    58  				}, nil
    59  			}
    60  
    61  			// \\host.example.com\Share\path\to\file
    62  			// becomes
    63  			// file://host.example.com/Share/path/to/file
    64  			return &url.URL{
    65  				Scheme: "file",
    66  				Host:   path[:i],
    67  				Path:   filepath.ToSlash(path[i:]),
    68  			}, nil
    69  		}
    70  
    71  		// C:\path\to\file
    72  		// becomes
    73  		// file:///C:/path/to/file
    74  		return &url.URL{
    75  			Scheme: "file",
    76  			Path:   "/" + filepath.ToSlash(path),
    77  		}, nil
    78  	}
    79  
    80  	// /path/to/file
    81  	// becomes
    82  	// file:///path/to/file
    83  	return &url.URL{
    84  		Scheme: "file",
    85  		Path:   filepath.ToSlash(path),
    86  	}, nil
    87  }