Many test suites have their test metadata defined in files called test manifests.
The build system does not enforce file naming for test manifest files. However, the following convention is used.
For the plain flavor of mochitests.
For the chrome flavor of mochitests.
For the browser chrome flavor of mochitests.
For the a11y flavor of mochitests.
For xpcshell tests.
ManifestParser manifests are essentially ini files that conform to a basic set of assumptions.
The reference documentation for manifestparser manifests describes the basic format of test manifests.
In summary, manifests are ini files with section names describing test files:
Keys under sections can hold metadata about each test:
[test_foo.js] skip-if = os == "win" [test_foo.js] skip-if = os == "linux" && debug [test_baz.js] fail-if = os == "mac" || os == "android"
There is a special DEFAULT section whose keys/metadata apply to all sections/tests:
[DEFAULT] property = value [test_foo.js]
In the above example, test_foo.js inherits the metadata property = value from the DEFAULT section.
Test manifests can define some common keys/metadata to influence behavior. Those keys are as follows:
List of files that will be executed before the test file. (Used in xpcshell tests.)
List of files that will be executed after the test file. (Used in xpcshell tests.)
List of additional files required to run tests. This is typically defined in the DEFAULT section.
Unlike other file lists, support-files supports a globbing mechanism to facilitate pulling in many files with minimal typing. This globbing mechanism is activated if an entry in this value contains a
*character. A single
*will wildcard match all files in a directory. A double
**will descend into child directories. For example,
Support files starting with
/are placed in a root directory, rather than a location determined by the manifest location. For mochitests, this allows for the placement of files at the server root. The source file is selected from the base name (e.g.,
/path/foo). Files starting with
/cannot be selected using globbing.
Some support files are used by tests across multiple directories. In this case, a test depending on a support file from another directory must note that dependency with the path to the required support file in its own support-files entry. These use a syntax where paths starting with
!/will indicate the beginning of the path to a shared support file starting from the root of the srcdir. For example, if a manifest at
dom/base/test/mochitest.inihas a support file,
dom/base/test/server-script.sjs, and a mochitest in
dom/workers/testdepends on that support file, the test manifest at
!/dom/base/test/server-script.sjsin its support-files entry.
List of files that are generated as part of the build and don’t exist in the source tree.
The build system assumes that each manifest file, test file, and file listed in head, tail, and support-files is static and provided by the source tree (and not automatically generated as part of the build). This variable tells the build system not to make this assumption.
This variable will likely go away sometime once all generated files are accounted for in the build config.
If a generated file is not listed in this key, a clobber build will likely fail.
Record that this manifest duplicates another manifest.
The common scenario is two manifest files will include a shared manifest file via the
[include:file]special section. The build system enforces that each test file is only provided by a single manifest. Having this key present bypasses that check.
The value of this key is ignored.
Skip this test if the specified condition is true. See Manifest Filter Language.
Expect test failure if the specified condition is true. See Manifest Filter Language.
If present, the test should not be run in parallel with other tests.
Some test harnesses support parallel test execution on separate processes and/or threads (behavior varies by test harness). If this key is present, the test harness should not attempt to run this test in parallel with any other test.
By convention, the value of this key is a string describing why the test can’t be run in parallel.
Manifest Filter Language¶
Some manifest keys accept a special filter syntax as their values. These values are essentially boolean expressions that are evaluated at test execution time.
The expressions can reference a well-defined set of variables, such as
debug. These variables are populated from the
mozinfo.json file. For the full list of available variables, see
the mozinfo documentation.
See the source for the full documentation of the expression syntax until it is documented here.
Files referenced by manifests are automatically installed into the object
directory into paths defined in
Relative paths resolving to parent directory (e.g.
support-files = ../foo.txt have special behavior.
support-files, the file will be installed to the default destination
for that manifest. Only the file’s base name is used to construct the final
path: directories are irrelevant. Files starting with
/ are an exception,
these are installed relative to the root of the destination; the base name is
instead used to select the file..
For all other entry types, the file installation is skipped.