Improve error messages for invalid version ranges operators (#16069)

* wip

* add checks

* wip

* wip

* wip

* Update conans/model/version_range.py

Co-authored-by: Antonin RAFFIN <antonin.raffin@ensta.org>

---------

Co-authored-by: Antonin RAFFIN <antonin.raffin@ensta.org>

conans/model/version_range.py

@@ -88,6 +88,8 @@ def _parse_expression(expression):
             if expression[1] == "=":
                 operator += "="
                 index = 2
+        elif expression[1] == "=":
+            raise ConanException(f"Invalid version range operator '{operator}=' in {expression}, you should probably use {operator} instead.")
         version = expression[index:]
         if version == "":
             raise ConanException(f'Error parsing version range "{expression}"')
@@ -111,7 +113,7 @@ def first_non_zero(main):
         else:
             return [_Condition(operator, Version(version))]
 
-    def _valid(self, version, conf_resolve_prepreleases):
+    def valid(self, version, conf_resolve_prepreleases):
         if version.pre:
             # Follow the expression desires only if core.version_ranges:resolve_prereleases is None,
             # else force to the conf's value
@@ -180,7 +182,7 @@ def contains(self, version: Version, resolve_prerelease: Optional[bool]):
         """
         assert isinstance(version, Version), type(version)
         for condition_set in self.condition_sets:
-            if condition_set._valid(version, resolve_prerelease):
+            if condition_set.valid(version, resolve_prerelease):
                 return True
         return False
 

conans/test/unittests/model/version/test_version_range.py

@@ -5,6 +5,7 @@
 from conans.model.version_range import VersionRange
 
 values = [
+    ['=1.0.0',  [[['=', '1.0.0']]],                   ["1.0.0"],          ["0.1"]],
     ['>1.0.0',  [[['>', '1.0.0']]],                   ["1.0.1"],          ["0.1"]],
     ['<2.0',    [[['<', '2.0-']]],                     ["1.0.1"],          ["2.1"]],
     ['>1 <2.0', [[['>', '1'], ['<', '2.0-']]],         ["1.5.1"],          ["0.1", "2.1"]],
@@ -109,7 +110,8 @@ def test_range_prereleases_conf(version_range, resolve_prereleases, versions_in,
 
 @pytest.mark.parametrize("version_range", [
     ">= 1.0",  # https://github.com/conan-io/conan/issues/12692
-    ">=0.0.1 < 1.0"  # https://github.com/conan-io/conan/issues/14612
+    ">=0.0.1 < 1.0",  # https://github.com/conan-io/conan/issues/14612
+    "==1.0",  "~=1.0",  "^=1.0", "v=1.0"  # https://github.com/conan-io/conan/issues/16066
 ])
 def test_wrong_range_syntax(version_range):
     with pytest.raises(ConanException):