filter-impossible-packages-only-required.test

--TEST--
When filtering packages from the pool that cannot meet the fixed/locked requirements, ensure that the requirements for a package that is not required anywhere is not used to filter, as it will be ultimately be removed.
(The locked third/pkg is not required by any package so will be removed, so should not restrict the versions of fourth/pkg)

--REQUEST--
{
    "require": {
        "first/pkg": "*",
        "second/pkg": "1.1.0"
    },
    "locked": [
        {"name": "first/pkg", "version": "1.0.0", "require": {"second/pkg": "^1.0"}},
        {"name": "second/pkg", "version": "1.0.0", "require": {"third/pkg": "1.0.0"}},
        {"name": "third/pkg", "version": "1.0.0", "require": {"fourth/pkg": "1.0.0"}},
        {"name": "fourth/pkg", "version": "1.0.0"}
    ],
    "allowList": [
        "first/pkg"
    ],
    "allowTransitiveDeps": true
}

--FIXED--
[
]

--PACKAGE-REPOS--
[
    [
        {"name": "first/pkg", "version": "1.0.0", "require": {"second/pkg": "*"}},
        {"name": "second/pkg", "version": "1.0.0", "require": {"third/pkg": "1.0.0"}},
        {"name": "second/pkg", "version": "1.1.0", "require": {"fourth/pkg": "2.0.0"}},
        {"name": "third/pkg", "version": "1.0.0", "require": {"fourth/pkg": "1.0.0"}},
        {"name": "fourth/pkg", "version": "1.0.0"},
        {"name": "fourth/pkg", "version": "2.0.0"}
    ]
]

--EXPECT--
[
    "third/pkg-1.0.0.0 (locked)",
    "first/pkg-1.0.0.0",
    "second/pkg-1.1.0.0",
    "fourth/pkg-1.0.0.0",
    "fourth/pkg-2.0.0.0"
]

--EXPECT-OPTIMIZED--
[
    "third/pkg-1.0.0.0 (locked)",
    "first/pkg-1.0.0.0",
    "second/pkg-1.1.0.0",
    "fourth/pkg-1.0.0.0",
    "fourth/pkg-2.0.0.0"
]