tests: path tweaks

The tests are written to assume you run them from the test directory.
Relax the assumption with a quick hack.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>

tests/test_edtlib.py

@@ -1,6 +1,7 @@
 # Copyright (c) 2019 Nordic Semiconductor ASA
 # SPDX-License-Identifier: BSD-3-Clause
 
+import contextlib
 import io
 from logging import WARNING
 import os
@@ -22,6 +23,18 @@ from devicetree import edtlib
 # bindings. The tests mostly use string comparisons via the various __repr__()
 # methods.
 
+HERE = os.path.dirname(__file__)
+
+@contextlib.contextmanager
+def from_here():
+    # Convenience hack to minimize diff from zephyr.
+    cwd = os.getcwd()
+    try:
+        os.chdir(HERE)
+        yield
+    finally:
+        os.chdir(cwd)
+
 def hpath(filename):
     '''Convert 'filename' to the host path syntax.'''
     return os.fspath(Path(filename))
@@ -29,7 +42,7 @@ def hpath(filename):
 def test_warnings(caplog):
     '''Tests for situations that should cause warnings.'''
 
-    edtlib.EDT("test.dts", ["test-bindings"])
+    with from_here(): edtlib.EDT("test.dts", ["test-bindings"])
 
     enums_hpath = hpath('test-bindings/enums.yaml')
     expected_warnings = [
@@ -45,6 +58,7 @@ def test_warnings(caplog):
 
 def test_interrupts():
     '''Tests for the interrupts property.'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
     filenames = {i: hpath(f'test-bindings/interrupt-{i}-cell.yaml')
                  for i in range(1, 4)}
@@ -66,6 +80,7 @@ def test_interrupts():
 
 def test_reg():
     '''Tests for the regs property'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
 
     assert str(edt.get_node("/reg-zero-address-cells/node").regs) == \
@@ -82,6 +97,7 @@ def test_reg():
 
 def test_pinctrl():
     '''Test 'pinctrl-<index>'.'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
 
     assert str(edt.get_node("/pinctrl/dev").pinctrls) == \
@@ -89,6 +105,7 @@ def test_pinctrl():
 
 def test_hierarchy():
     '''Test Node.parent and Node.children'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
 
     assert edt.get_node("/").parent is None
@@ -106,6 +123,7 @@ def test_hierarchy():
 
 def test_include():
     '''Test 'include:' and the legacy 'inherits: !include ...' in bindings'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
 
     assert str(edt.get_node("/binding-include").description) == \
@@ -116,6 +134,7 @@ def test_include():
 
 def test_bus():
     '''Test 'bus:' and 'on-bus:' in bindings'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
 
     assert edt.get_node("/buses/foo-bus").bus == "foo"
@@ -159,6 +178,7 @@ def test_bus():
 
 def test_child_binding():
     '''Test 'child-binding:' in bindings'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
     child1 = edt.get_node("/child-binding/child-1")
     child2 = edt.get_node("/child-binding/child-2")
@@ -176,6 +196,7 @@ def test_child_binding():
     assert str(grandchild.description) == "grandchild node"
     assert str(grandchild.props) == "OrderedDict([('grandchild-prop', <Property, name: grandchild-prop, type: int, value: 2>)])"
 
+    with from_here():
         binding_file = Path("test-bindings/child-binding.yaml").resolve()
         top = edtlib.Binding(binding_file, {})
     child = top.child_binding
@@ -184,6 +205,7 @@ def test_child_binding():
     assert top.compatible == 'top-binding'
     assert child.compatible is None
 
+    with from_here():
         binding_file = Path("test-bindings/child-binding-with-compat.yaml").resolve()
         top = edtlib.Binding(binding_file, {})
     child = top.child_binding
@@ -194,6 +216,7 @@ def test_child_binding():
 
 def test_props():
     '''Test Node.props (derived from DT and 'properties:' in the binding)'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
     filenames = {i: hpath(f'test-bindings/phandle-array-controller-{i}.yaml')
                  for i in range(0, 4)}
@@ -242,6 +265,7 @@ def test_props():
 
 def test_nexus():
     '''Test <prefix>-map via gpio-map (the most common case).'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
     filename = hpath('test-bindings/gpio-dst.yaml')
 
@@ -250,6 +274,7 @@ def test_nexus():
 
 def test_prop_defaults():
     '''Test property default values given in bindings'''
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
 
     assert str(edt.get_node("/defaults").props) == \
@@ -258,6 +283,7 @@ def test_prop_defaults():
 def test_prop_enums():
     '''test properties with enum: in the binding'''
 
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"])
     props = edt.get_node('/enums').props
     int_enum = props['int-enum']
@@ -295,10 +321,12 @@ def test_prop_enums():
 def test_binding_inference():
     '''Test inferred bindings for special zephyr-specific nodes.'''
     warnings = io.StringIO()
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"], warnings)
 
     assert str(edt.get_node("/zephyr,user").props) == r"OrderedDict()"
 
+    with from_here():
         edt = edtlib.EDT("test.dts", ["test-bindings"], warnings,
                          infer_binding_for_paths=["/zephyr,user"])
     filenames = {i: hpath(f'test-bindings/phandle-array-controller-{i}.yaml')
@@ -309,6 +337,7 @@ def test_binding_inference():
 
 def test_multi_bindings():
     '''Test having multiple directories with bindings'''
+    with from_here():
         edt = edtlib.EDT("test-multidir.dts", ["test-bindings", "test-bindings-2"])
 
     assert str(edt.get_node("/in-dir-1").binding_path) == \
@@ -319,6 +348,7 @@ def test_multi_bindings():
 
 def test_dependencies():
     ''''Test dependency relations'''
+    with from_here():
         edt = edtlib.EDT("test-multidir.dts", ["test-bindings", "test-bindings-2"])
 
     assert edt.get_node("/").dep_ordinal == 0