Add ability to reference files in the local filesystem with file:// s…

conan/tools/files/files.py

@@ -11,6 +11,7 @@
 from fnmatch import fnmatch
 
 import six
+import urllib
 
 from conan.tools import CONAN_TOOLCHAIN_ARGS_FILE, CONAN_TOOLCHAIN_ARGS_SECTION
 from conan.tools.apple.apple import is_apple_os
@@ -164,13 +165,21 @@ def download(conanfile, url, filename, verify=True, retry=None, retry_wait=None,
     download_cache = config["tools.files.download:download_cache"] if checksum else None
 
     def _download_file(file_url):
-        # The download cache is only used if a checksum is provided, otherwise, a normal download
-        run_downloader(requester=requester, output=out, verify=verify, download_cache=download_cache,
-                       user_download=True, url=file_url,
-                       file_path=filename, retry=retry, retry_wait=retry_wait, overwrite=overwrite,
-                       auth=auth, headers=headers, md5=md5, sha1=sha1, sha256=sha256)
+        if file_url.startswith('file:'):
+            filepath = _path_from_file_uri(file_url)
+            shutil.copyfile(filepath, filename)
+        else:
+            # The download cache is only used if a checksum is provided, otherwise, a normal download
+            run_downloader(requester=requester, output=out, verify=verify, download_cache=download_cache,
+                        user_download=True, url=file_url,
+                        file_path=filename, retry=retry, retry_wait=retry_wait, overwrite=overwrite,
+                        auth=auth, headers=headers, md5=md5, sha1=sha1, sha256=sha256)
         out.writeln("")
 
+    def _path_from_file_uri(uri):
+       path = urllib.parse.urlparse(uri).path
+       return urllib.request.url2pathname(path)
+
     if not isinstance(url, (list, tuple)):
         _download_file(url)
     else:  # We were provided several URLs to try

conans/requirements_dev.txt

@@ -1,6 +1,7 @@
 pytest>=6.1.1, <7.0.0; python_version > '3.0'
 pytest>=4.6.11; python_version < '3.0'
 pytest-xdist  # To launch in N cores with pytest -n
+pyfakefs>=4.5.6
 parameterized>=0.6.3
 mock>=1.3.0, <1.4.0
 WebTest>=2.0.18, <2.1.0

conans/test/unittests/tools/files/test_downloads.py

@@ -1,4 +1,5 @@
 import os
+import platform
 
 import pytest
 import requests
@@ -157,6 +158,32 @@ def test_download_no_retries_errors(self, bottle_server):
         assert "Waiting" not in str(conanfile.output)
         assert "retry" not in str(conanfile.output)
 
+    def test_download_localfile(self, fs):
+        conanfile = ConanFileMock()
+        conanfile._conan_requester = requests
+
+        file_location = '/path/to/file.txt'
+        if platform.system() == "Windows":
+            file_location = "C:" + file_location
+        fs.create_file(file_location, contents='this is some content')
+        file_url = f"file:///{file_location}"
+
+        dest = os.path.join(temp_folder(), "file.txt")
+        download(conanfile, file_url, dest)
+        content = load(dest)
+        assert "this is some content" == content
+
+    def test_download_localfile_notfound(self):
+        conanfile = ConanFileMock()
+        conanfile._conan_requester = requests
+
+        file_url = "file:///path/to/missing/file.txt"
+        dest = os.path.join(temp_folder(), "file.txt")
+
+        with pytest.raises(FileNotFoundError) as exc:
+            download(conanfile, file_url, dest)
+
+        assert "No such file" in str(exc.value)
 
 @pytest.fixture()
 def bottle_server_zip():