Look for vswhere in PATH when using tools.vswhere() (#4805)

* Test vswhere found in path too

* Look for vswhere in PATH when using tools.vswhere()

* improvement

* test

conans/client/tools/win.py

@@ -7,6 +7,7 @@
 
 import deprecation
 
+from conans.client.tools import which
 from conans.client.tools.env import environment_append
 from conans.client.tools.oss import OSInfo, detected_architecture
 from conans.errors import ConanException
@@ -250,15 +251,19 @@ def vswhere(all_=False, prerelease=False, products=None, requires=None, version=
         raise ConanException("The 'legacy' parameter cannot be specified with either the "
                              "'products' or 'requires' parameter")
 
-    program_files = os.environ.get("ProgramFiles(x86)", os.environ.get("ProgramFiles"))
-
+    installer_path = None
+    vswhere_in_path = which("vswhere")
+    program_files = get_env("ProgramFiles(x86)") or get_env("ProgramFiles")
     if program_files:
-        vswhere_path = os.path.join(program_files, "Microsoft Visual Studio", "Installer",
-                                    "vswhere.exe")
-        if not os.path.isfile(vswhere_path):
-            raise ConanException("Cannot locate 'vswhere'")
-    else:
-        raise ConanException("Cannot locate 'Program Files'/'Program Files (x86)' directory")
+        expected_path = os.path.join(program_files, "Microsoft Visual Studio", "Installer",
+                                     "vswhere.exe")
+        if os.path.isfile(expected_path):
+            installer_path = expected_path
+    vswhere_path = installer_path or vswhere_in_path
+
+    if not vswhere_path:
+        raise ConanException("Cannot locate vswhere in 'Program Files'/'Program Files (x86)' "
+                             "directory nor in PATH")
 
     arguments = list()
     arguments.append(vswhere_path)

conans/test/unittests/util/tools_test.py

@@ -37,6 +37,7 @@
 from conans.test.utils.tools import SVNLocalRepoTestCase, StoppableThreadBottle, \
     TestBufferConanOutput, TestClient, create_local_git_repo, try_remove_readonly
 from conans.tools import get_global_instances
+from conans.util.env_reader import get_env
 from conans.util.files import load, md5, mkdir, save
 
 
@@ -794,6 +795,30 @@ def vswhere_description_strip_test(self):
             json = vswhere()
             self.assertNotIn("descripton", json)
 
+    @unittest.skipUnless(platform.system() == "Windows", "Requires vswhere")
+    def vswhere_path_test(self):
+        # vswhere not found
+        with tools.environment_append({"ProgramFiles": None, "ProgramFiles(x86)": None, "PATH": ""}):
+            with self.assertRaisesRegex(ConanException, "Cannot locate vswhere"):
+                vswhere()
+        # vswhere in ProgramFiles
+        program_files = get_env("ProgramFiles(x86)") or get_env("ProgramFiles")
+        vswhere_path = None
+        if program_files:
+            expected_path = os.path.join(program_files, "Microsoft Visual Studio", "Installer",
+                                         "vswhere.exe")
+            if os.path.isfile(expected_path):
+                vswhere_path = expected_path
+                with tools.environment_append({"PATH": ""}):
+                    self.assertTrue(vswhere())
+        # vswhere in PATH
+        env = {"ProgramFiles": None, "ProgramFiles(x86)": None}
+        if not which("vswhere") and vswhere_path:
+                vswhere_folder = os.path.join(program_files, "Microsoft Visual Studio", "Installer")
+                env.update({"PATH": [vswhere_folder]})
+        with tools.environment_append(env):
+            self.assertTrue(vswhere())
+
     def vcvars_echo_test(self):
         if platform.system() != "Windows":
             return