Custom Input Annotations

Custom input annotations allow particular inputs to be recommended to Diffblue Cover when writing tests.

Using @InTestsUseEnums

The @InTestsUseEnums annotation allows the user to recommend specific Enum values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated with the names of specific enum values preferred by the developer:

public static boolean isDateOrTimeBased(@InTestsUseEnums({"SECONDS", "YEARS", "FOREVER"}) ChronoUnit chronoUnit) {
    return chronoUnit.isDateBased() || chronoUnit.isTimeBased();
}

Using @InTestsUseCharacters

The @InTestsUseCharacters annotation allows the user to recommend specific char values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated with a genuine examples characters that make up a Unicode surrogate pair that can be used to achieve a positive test:

@Nullable
public static Integer toNullableCodePoint(
        @InTestsUseCharacters('\uD801') char high,
        @InTestsUseCharacters('\uDC37') char low) {
    if (Character.isSurrogatePair(high, low)) {
        return Character.toCodePoint(high, low);
    }
    return null;
}

Using @InTestsUseBytes

The @InTestsUseBytes annotation allows the user to recommend specific byte values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated to use a specific preferred value:

public static String toUpperHexString(@InTestsUseBytes((byte)0xD1) byte input) {
    return Long.toHexString(input).toUpperCase();
}

Using @InTestsUseShorts

The @InTestsUseShorts annotation allows the user to recommend specific short values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated to use a specific preferred value:

public static String toUpperHexString(@InTestsUseShorts((short)0xD1FF) short input) {
    return Long.toHexString(input).toUpperCase();
}

Using @InTestsUseIntegers

The @InTestsUseIntegers annotation allows the user to recommend specific int values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated to use a specific preferred value:

public static String toUpperHexString(@InTestsUseIntegers(0xD1FFB) int input) {
    return Long.toHexString(input).toUpperCase();
}

Using @InTestsUseLongs

The @InTestsUseLongs annotation allows the user to recommend specific long values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated to use a specific preferred value:

public static String toUpperHexString(@InTestsUseLongs(0xD1FFBL) long input) {
    return Long.toHexString(input).toUpperCase();
}

Using @InTestsUseFloats

The @InTestsUseFloats annotation allows the user to recommend specific float values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated to use a specific preferred value:

public static boolean isNearPi(@InTestsUseFloats(3.14159f) float input) {
    return Float.toString(input).startsWith("3.14");
}

Using @InTestsUseDoubles

The @InTestsUseDoubles annotation allows the user to recommend specific double values to use in tests. Sometimes this can be useful to control the values used for cosmetic reasons, but it can also be useful when Cover is unable to identify values to cover all cases. For example the following method is annotated to use a specific preferred value:

public static boolean isNearPi(@InTestsUseDoubles(Math.PI) float input) {
    return Double.toString(input).startsWith("3.14");
}