Combining patterns

Include and exclude paths

A GlobCollection matches a path when at least one of its patterns includes it and none excludes it. A pattern that starts with a ! is an exclude pattern:

GlobCollection globs =
[
    Glob.Parse("**/*.cs", GlobDialect.Standard),
    Glob.Parse("!**/obj/**", GlobDialect.Standard),
];

Assert.True(globs.IsMatch("src/Program.cs"));
Assert.False(globs.IsMatch("src/obj/Debug/AssemblyInfo.cs"));
Assert.False(globs.IsMatch("readme.md"));

• Create the collection with a collection expression, as above, or with new GlobCollection(glob1, glob2).
• The Mode property of a Glob tells whether it includes (GlobMode.Include) or excludes (GlobMode.Exclude) paths. On its own, an exclude pattern still matches the paths it describes: the exclusion happens in the collection.
• A collection can hold other collections, since both implement IGlobEvaluatable.

Exclude patterns always win

The order of the patterns does not matter: a path that matches an exclude pattern is excluded, even when an include pattern written after it matches the path too.

// The order does not matter: a path that matches an exclude pattern is excluded
GlobCollection globs =
[
    Glob.Parse("!*.log", GlobDialect.Standard),
    Glob.Parse("*", GlobDialect.Standard),
    Glob.Parse("important.log", GlobDialect.Standard),
];

Assert.True(globs.IsMatch("readme.md"));
Assert.False(globs.IsMatch("important.log"));

To re-include a path, as ! does in a .gitignore file, use a collection created from gitignore content: its last matching pattern decides. See Reading .gitignore files.

Exclude the content of a directory

In the standard dialect, a pattern that ends with a / matches the directory only. Excluding it does not exclude the files it holds: exclude dir/** instead.

// '!obj/' excludes the directory itself, not the files it holds
GlobCollection directoryOnly = [Glob.Parse("**/*", GlobDialect.Standard), Glob.Parse("!obj/", GlobDialect.Standard)];
Assert.True(directoryOnly.IsMatch("obj/project.assets.json"));

// '!obj/**' excludes everything below the directory
GlobCollection content = [Glob.Parse("**/*", GlobDialect.Standard), Glob.Parse("!obj/**", GlobDialect.Standard)];
Assert.False(content.IsMatch("obj/project.assets.json"));

obj/ and obj/** only match at the root. Write **/obj/** to exclude every obj directory, at any depth.

Enumerate the files of a collection

EnumerateFiles and EnumerateFileSystemEntries work on a collection as on a single pattern:

using var rootDirectory = TemporaryDirectory.Create();
rootDirectory.CreateEmptyFile("src/App/Program.cs");
rootDirectory.CreateEmptyFile("src/App/obj/Debug/AssemblyInfo.cs");
rootDirectory.CreateEmptyFile("tests/AppTests.cs");

GlobCollection globs =
[
    Glob.Parse("src/**/*.cs", GlobDialect.Standard),
    Glob.Parse("!**/obj/**", GlobDialect.Standard),
];

var files = globs.EnumerateFiles(rootDirectory.FullPath).ToList();
Assert.Equal([Path.Combine(rootDirectory.FullPath, "src", "App", "Program.cs")], files);

The include patterns decide which directories are visited: the enumeration starts at the base directory of each include pattern, and visits a directory once when several patterns share it. The enumeration does not go into a directory when an exclude pattern matches everything below it, such as !**/node_modules/** or !**/bin/**/*, so a large excluded tree is not read. A pattern that only excludes some of the files of a directory, such as !**/*.log, does not stop the enumeration from reading the directory.

In the standard dialect, ** does not match a name that starts with a dot, so !**/node_modules/** does not exclude node_modules/.bin/tool. The directory is still skipped when the include patterns cannot match such a name either, which is the case unless they use GlobOptions.MatchLeadingDot.

GlobCollection globs =
[
    Glob.Parse("**/*", GlobDialect.Standard),
    Glob.Parse("!**/node_modules/**", GlobDialect.Standard),
];

// The exclude pattern matches the whole content of node_modules: the enumeration does not go into it
Assert.False(globs.IsPartialMatch("src/node_modules"));
Assert.True(globs.IsPartialMatch("src/app"));