Allow executing tests from outside the suite

If btest.cfg is in the `testing/btest` relative directory, this allows
the user to call btest with `btest testing/btest/tests`, which will use
the btest.cfg file in testing/btest. It will also check its parents, so
you may use `btest testing/btest/language/while.zeek` - for example.

The first complication is that previously-valid uses of btest should
remain the same. This is done by always checking the current directory
for btest.cfg first.

The second is if there is a conflict between two tests' btest.cfg file.
For example, the following may choose two different btest.cfg files:

.
└── multiple-cfg
    ├── Baseline
    ├── btest.cfg
    └── tests
        ├── no-cfg
        │   └── test2.test
        └── with-cfg
            ├── btest.cfg
            └── tests
                └── test1.test

If there is a conflicting config file, then btest should raise an error,
as it can currently only execute with one config file per run.

Author: evantypanski

btest

@@ -2713,18 +2713,24 @@ def outputDocumentation(tests, fmt):
             print()
 
 
-# Finds a file, recursing to parent directories if not found
-def find_file(filename, *, recurse):
-    current_dir = pathlib.Path.cwd()
+# Finds the config file 'filename', recursing to parent directories from the
+# 'start_dir' if not found.
+def find_config_file(filename, *, start_dir, recurse):
+    # First check current dir
+    f = pathlib.Path(filename)
+    if f.is_file():
+        return str(f.absolute())
+
+    if not recurse:
+        return None
+
+    current_dir = start_dir.absolute()
 
     for d in [current_dir, *current_dir.parents]:
         f = d / filename
         if f.is_file():
             return str(f)
 
-        if not recurse:
-            break
-
     return None
 
 
@@ -3008,20 +3014,50 @@ if __name__ == "__main__":
 
     (Options, args) = parse_options()
 
-    btest_cfg = find_file(Options.config, recurse=Options.config == DEFAULT_CONFIG_NAME)
-    if not btest_cfg:
+    found_configs = set()
+
+    if args:
+        for arg in args:
+            if found_config := find_config_file(
+                Options.config,
+                start_dir=pathlib.Path(arg).absolute(),
+                recurse=Options.config == DEFAULT_CONFIG_NAME,
+            ):
+                found_configs.add(found_config)
+    else:
+        if found_config := find_config_file(
+            Options.config,
+            start_dir=pathlib.Path.cwd(),
+            recurse=Options.config == DEFAULT_CONFIG_NAME,
+        ):
+            found_configs.add(found_config)
+
+    if len(found_configs) == 0:
         error(f"configuration file '{Options.config}' not found")
 
+    if len(found_configs) > 1:
+        conflicting_configs = ", ".join(
+            sorted(f"'{config}'" for config in found_configs)
+        )
+        error(
+            f"cannot execute tests using different configuration files together: {conflicting_configs}"
+        )
+
+    btest_cfg = found_configs.pop()
+
+    dirname = os.path.dirname(btest_cfg)
+
+    # Special case for providing just a single path to btest that happens
+    # to be the TestBase. Reset args, assuming the user wants to run all tests.
+    if len(args) == 1 and os.path.abspath(args[0]) == dirname:
+        args = []
+
     # The defaults come from environment variables, plus a few additional items.
     defaults = {}
     # Changes to defaults should not change os.environ
     defaults.update(os.environ)
     defaults["default_path"] = os.environ["PATH"]
 
-    dirname = os.path.dirname(btest_cfg)
-    if not dirname:
-        dirname = os.getcwd()
-
     # If the BTEST_TEST_BASE envirnoment var is set, we'll use that as the testbase.
     # If not, we'll use the config file's directory.
     TestBase = normalize_path(os.environ.get("BTEST_TEST_BASE", dirname))

testing/Baseline/tests.multiple-cfg-fail/output

@@ -0,0 +1,13 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+## RUNNING NO CFG TEST ALONE
+tests.no-cfg.no-cfg ...
+  > exit 0
+... tests.no-cfg.no-cfg ok
+all 1 tests successful
+## RUNNING WITH CFG TEST ALONE
+tests.with-cfg ...
+  > exit 0
+... tests.with-cfg ok
+all 1 tests successful
+## RUNNING TESTS TOGETHER
+cannot execute tests using different configuration files together: '<...>/btest.cfg', '<...>/btest.cfg'

testing/Baseline/tests.outside-btest-dir/output

@@ -0,0 +1,17 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+## RUNNING DIRECTLY ON DIRECTORY WITH CONFIG:
+tests.one.a-relative-test ...
+  > exit 0
+... tests.one.a-relative-test ok
+tests.two.another-relative-test ...
+  > exit 0
+... tests.two.another-relative-test ok
+all 2 tests successful
+## RUNNING DIRECTLY ON TESTS DIRECTORY:
+tests.one.a-relative-test ...
+  > exit 0
+... tests.one.a-relative-test ok
+tests.two.another-relative-test ...
+  > exit 0
+... tests.two.another-relative-test ok
+all 2 tests successful

testing/Scripts/diff-remove-abspath

@@ -2,4 +2,8 @@
 #
 # Replace absolute paths with the basename.
 
-sed 's#[a-zA-Z:]*/\([^/]\{1,\}/\)\{1,\}\([^/]\{1,\}\)#<...>/\2#g'
+# The drive letter portion of the Windows regex below is adapted from
+# https://github.com/stdlib-js/stdlib/blob/develop/lib/node_modules/%40stdlib/regexp/basename-windows/lib/regexp.js
+sed -E 's#/+#/#g' |
+    sed -E 's#([a-zA-Z]:|[\\/]{2}[^\\/]+[\\/]+[^\\/]+)([\\/])([^	 :\\/]{1,}[\\/]){1,}([^	 :\\/]{1,})#<...>/\4#g' |
+    sed -E 's#/([^	 :/]{1,}/){1,}([^	 :/]{1,})#<...>/\2#g'

testing/btest.tests.cfg

@@ -10,6 +10,7 @@ override=normal
 [btest]
 TmpDir      = `echo .tmp`
 BaselineDir = %(testbase)s/Baseline
+TestDirs    = tests
 
 [environment]
 ORIGPATH=%(default_path)s

testing/tests/multiple-cfg-fail.test

@@ -0,0 +1,20 @@
+# %TEST-DOC: Test that you can run btest from outside of the directory with btest.cfg
+#
+# %TEST-EXEC: mkdir -p base/tests/no-cfg
+# %TEST-EXEC: mkdir -p base/tests/with-cfg/tests
+# %TEST-EXEC: cat %INPUT >> base/tests/no-cfg/no-cfg.test
+# %TEST-EXEC: mv btest.cfg base/
+# %TEST-EXEC: echo "## RUNNING NO CFG TEST ALONE" >>output
+# %TEST-EXEC: btest -v base/tests/no-cfg/no-cfg.test >>output 2>&1
+#
+# %TEST-EXEC: cp base/btest.cfg base/tests/with-cfg
+# %TEST-EXEC: cat %INPUT >> base/tests/with-cfg/tests/with-cfg.test
+# %TEST-EXEC: echo "## RUNNING WITH CFG TEST ALONE" >>output
+# %TEST-EXEC: btest -v base/tests/with-cfg/tests/with-cfg.test >>output 2>&1
+#
+# But fail together
+# %TEST-EXEC: echo "## RUNNING TESTS TOGETHER" >>output
+# %TEST-EXEC-FAIL: btest -v base/tests/no-cfg/no-cfg.test base/tests/with-cfg/tests/with-cfg.test >>output 2>&1
+# %TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff output
+
+@TEST-EXEC: exit 0

testing/tests/outside-btest-dir.test

@@ -0,0 +1,18 @@
+# %TEST-DOC: Test that you can run btest from outside of the directory with btest.cfg
+#
+# %TEST-EXEC: mkdir -p base/tests/one
+# %TEST-EXEC: mkdir -p base/tests/two
+# %TEST-EXEC: cat %INPUT >> base/tests/one/a-relative-test.test
+# %TEST-EXEC: cat %INPUT >> base/tests/two/another-relative-test.test
+# %TEST-EXEC: mv btest.cfg base/
+# %TEST-EXEC: btest base/tests/one/a-relative-test.test
+# %TEST-EXEC: btest base/tests/one/a-relative-test.test base/tests/two/another-relative-test.test
+#
+# Test the special case of running all tests from outside
+# %TEST-EXEC: echo "## RUNNING DIRECTLY ON DIRECTORY WITH CONFIG:" >>output
+# %TEST-EXEC: btest -v base/ >>output 2>&1
+# %TEST-EXEC: echo "## RUNNING DIRECTLY ON TESTS DIRECTORY:" >>output
+# %TEST-EXEC: btest -v base/tests >>output 2>&1
+# %TEST-EXEC: btest-diff output
+
+@TEST-EXEC: exit 0