Add HIGHS to tests and ignore those which fail due to unavailable features

Author: tuliotoffolo

mip/__init__.py

@@ -7,6 +7,10 @@
 from mip.ndarray import LinExprTensor
 from mip.entities import Column, Constr, LinExpr, Var, ConflictGraph
 from mip.model import *
-from mip._version import __version__
+
+try:
+    from ._version import __version__
+except ImportError:
+    __version__ = "unknown"
 
 name = "mip"

mip/gurobi.py

@@ -51,6 +51,7 @@
 MAX_NAME_SIZE = 512  # for variables and constraints
 
 lib_path = None
+has_gurobi = False
 
 if "GUROBI_HOME" in environ:
     if platform.lower().startswith("win"):
@@ -93,9 +94,9 @@
 
 
 if lib_path is None:
-    found = False
+    has_gurobi = False
 else:
-    found = True
+    has_gurobi = True
     grblib = ffi.dlopen(lib_path)
 
     ffi.cdef(
@@ -339,7 +340,7 @@ class SolverGurobi(Solver):
     def __init__(self, model: Model, name: str, sense: str, modelp: CData = ffi.NULL):
         """modelp should be informed if a model should not be created,
         but only allow access to an existing one"""
-        if not found:
+        if not has_gurobi:
             raise FileNotFoundError(
                 """Gurobi not found. Plase check if the
             Gurobi dynamic loadable library is reachable or define

mip/model.py

@@ -4,7 +4,11 @@
 from typing import List, Tuple, Optional, Union, Dict, Any
 import numbers
 import mip
-from ._version import __version__
+
+try:
+    from ._version import __version__
+except ImportError:
+    __version__ = "unknown"
 
 logger = logging.getLogger(__name__)
 
@@ -94,8 +98,7 @@ def __init__(
             else:
                 import mip.gurobi
 
-                if mip.gurobi.found:
-
+                if mip.gurobi.has_gurobi:
                     self.solver = mip.gurobi.SolverGurobi(self, name, sense)
                     self.solver_name = mip.GUROBI
                 else:
@@ -406,7 +409,7 @@ def clear(self: "Model"):
             # checking which solvers are available
             import mip.gurobi
 
-            if mip.gurobi.found:
+            if mip.gurobi.has_gurobi:
                 self.solver = mip.gurobi.SolverGurobi(self, self.name, sense)
                 self.solver_name = mip.GUROBI
             else:

test/examples_test.py

@@ -8,12 +8,17 @@
 import importlib.machinery
 import pytest
 
+import mip.gurobi
+import mip.highs
+from mip import CBC, GUROBI, HIGHS
 
 EXAMPLES = glob(join("..", "examples", "*.py")) + glob(join(".", "examples", "*.py"))
 
-SOLVERS = ["cbc"]
-if "GUROBI_HOME" in environ:
-    SOLVERS += ["gurobi"]
+SOLVERS = [CBC]
+if mip.gurobi.has_gurobi:
+    SOLVERS += [GUROBI]
+if mip.highs.has_highs:
+    SOLVERS += [HIGHS]
 
 
 @pytest.mark.parametrize("solver, example", product(SOLVERS, EXAMPLES))
@@ -22,4 +27,7 @@ def test_examples(solver, example):
     environ["SOLVER_NAME"] = solver
     loader = importlib.machinery.SourceFileLoader("example", example)
     mod = types.ModuleType(loader.name)
-    loader.exec_module(mod)
+    try:
+        loader.exec_module(mod)
+    except NotImplementedError as e:
+        print("Skipping test for example '{}': {}".format(example, e))

test/test_gurobi.py

@@ -1,12 +1,13 @@
 import pytest
 
 import mip
+import mip.gurobi
 
 
 def test_gurobi_pip_installation():
     # Even though we have no valid license yet, we could check that the binaries are found.
     # If no valid license is found, an InterfacingError is thrown
 
-    with pytest.raises(mip.InterfacingError):
-        mip.Model(solver_name="GRB")
-
+    if mip.gurobi.has_gurobi:
+        with pytest.raises(mip.InterfacingError):
+            mip.Model(solver_name=mip.GUROBI)