Test that WI.CSSStyleDeclaration.prototype.resolveVariableValue works as expected. == Running test suite: WI.CSSStyleDeclaration.prototype.resolveVariableValue -- Running test case: NotVariable PASS: "red" should resolve to null. -- Running test case: EmptyVariable PASS: "var()" should resolve to null. -- Running test case: InvalidVariable PASS: "var(invalid)" should resolve to null. -- Running test case: NonExistentVariable PASS: "var(--DNE)" should resolve to null. -- Running test case: ValidVariable PASS: "var(--a)" should resolve to "blue". -- Running test case: InvalidFallbackValue PASS: "var(--DNE, )" should resolve to null. -- Running test case: ValidFallbackValue PASS: "var(--DNE, red)" should resolve to "red". -- Running test case: InvalidFallbackVariable PASS: "var(--DNE, var(--DNE))" should resolve to null. -- Running test case: ValidFallbackVariable PASS: "var(--DNE, var(--b, red))" should resolve to "green". -- Running test case: ValidVariableWithInvalidFallbackValue PASS: "var(--a, )" should resolve to "blue". -- Running test case: ValidVariableWithValidFallbackValue PASS: "var(--a, red)" should resolve to "blue". -- Running test case: ValidVariableWithInvalidFallbackVariable PASS: "var(--a, var(--DNE))" should resolve to "blue". -- Running test case: ValidVariableWithValidFallbackVariable PASS: "var(--a, var(--b))" should resolve to "blue".