android - 使用 “hasBackground” 进行 Espresso 测试

Question

如何使用布局背景的颜色进行 Espresso 测试？目前使用hasBackground() :

onView(withId(R.id.backgroundColor)).check(matches(hasBackground(Color.parseColor("#FF55ff77"))));

但是出现错误:

android.support.test.espresso.base.DefaultFailureHandler$AssertionFailedWithCauseError: 'has background with drawable ID: -11141257' doesn't match the selected view.

Expected: has background with drawable ID: -11141257

Got: "LinearLayout{id=2130968576, res-name=backgroundColor, visibility=VISIBLE, width=996, height=1088, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, layout-params=android.widget.LinearLayout$LayoutParams@e55f6e7, tag=null, root-is-layout-requested=false, has-input-connection=false, x=42.0, y=601.0, child-count=2}"

我如何比较这个？

Answer 1

我在 Hamcrest 的帮助下使用自定义匹配器来完成它库:

public class BackgroundColourMatcher extends TypeSafeMatcher<View> {

    @ColorRes
    private final int mExpectedColourResId;

    private int mColorFromView;

    public BackgroundColourMatcher(@ColorRes int expectedColourResId) {
        super(View.class);
        mExpectedColourResId = expectedColourResId;
    }

    @Override
    protected boolean matchesSafely(View item) {

        if (item.getBackground() == null) {
            return false;
        }
        Resources resources = item.getContext().getResources();
        int colourFromResources = ResourcesCompat.getColor(resources, mExpectedColourResId, null);
        mColorFromView = ((ColorDrawable) item.getBackground()).getColor();
        return mColorFromView == colourFromResources;
    }

    @Override
    public void describeTo(Description description) {
        description.appendText("Color did not match " + mExpectedColourResId + " was " + mColorFromView);
    }
}

你可以为你的匹配器提供类似的东西:

public class CustomTestMatchers {

    public static Matcher<View> withBackgroundColour(@ColorRes int expectedColor) {
        return new BackgroundColourMatcher(expectedColor);
    }
}

最后在你的测试中:

onView(withId(R.id.my_view)).check(matches(withBackgroundColour(R.color.color_to_check)))

您可以轻松修改 BackgroundColourMatcher 类，使其直接使用颜色而不是资源。

希望对您有所帮助!