package com.example.util.nullability;
import com.crashlytics.android.Crashlytics;
import javax.annotation.Nullable;
/**
* Stripped down version of Guava preconditions. We added an extra feature on the Preconditions class and that is to log the exceptions in
* crashlytics. This appear in the dashboard as "non-fatal" exceptions.
*/
@SuppressWarnings("all")
public final class Preconditions {
private Preconditions() {
throw new AssertionError();
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* @param expression a boolean expression
*
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(boolean expression) {
if (!expression) {
IllegalArgumentException illegalArgumentException = new IllegalArgumentException("Argument failed check.");
Crashlytics.logException(illegalArgumentException);
throw illegalArgumentException;
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessage the exception message to use if the check fails; will be converted to a
* string using {@link String#valueOf(Object)}
*
* @throws IllegalArgumentException if {@code expression} is false
*/
public static void checkArgument(boolean expression, @Nullable Object errorMessage) {
if (!expression) {
IllegalArgumentException illegalArgumentException = new IllegalArgumentException(String.valueOf(errorMessage));
Crashlytics.logException(illegalArgumentException);
throw illegalArgumentException;
}
}
/**
* Ensures the truth of an expression involving one or more parameters to the calling method.
*
* @param expression a boolean expression
* @param errorMessageTemplate a template for the exception message should the check fail. The
* message is formed by replacing each {@code %s} placeholder in the template with an
* argument. These are matched by position - the first {@code %s} gets {@code
* errorMessageArgs[0]}, etc. Unmatched arguments will be appended to the formatted message
* in square braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message template. Arguments
* are converted to strings using {@link String#valueOf(Object)}.
*
* @throws IllegalArgumentException if {@code expression} is false
* @throws NullPointerException if the check fails and either {@code errorMessageTemplate} or
* {@code errorMessageArgs} is null (don't let this happen)
*/
public static void checkArgument(boolean expression,
@Nullable String errorMessageTemplate,
@Nullable Object... errorMessageArgs) {
if (!expression) {
IllegalArgumentException illegalArgumentException = new IllegalArgumentException(format(errorMessageTemplate, errorMessageArgs));
Crashlytics.logException(illegalArgumentException);
throw illegalArgumentException;
}
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* @param reference an object reference
*
* @return the non-null reference that was validated
*
* @throws NullPointerException if {@code reference} is null
*/
public static <T> T checkNotNull(@Nullable T reference) {
if (reference == null) {
NullPointerException nullPointerException = new NullPointerException("Null check failed.");
Crashlytics.logException(nullPointerException);
throw nullPointerException;
}
return reference;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* @param reference an object reference
* @param errorMessage the exception message to use if the check fails; will be converted to a
* string using {@link String#valueOf(Object)}
*
* @return the non-null reference that was validated
*
* @throws NullPointerException if {@code reference} is null
*/
public static <T> T checkNotNull(T reference, @Nullable Object errorMessage) {
if (reference == null) {
NullPointerException nullPointerException = new NullPointerException(String.valueOf(errorMessage));
Crashlytics.logException(nullPointerException);
throw nullPointerException;
}
return reference;
}
/**
* Ensures that an object reference passed as a parameter to the calling method is not null.
*
* @param reference an object reference
* @param errorMessageTemplate a template for the exception message should the check fail. The
* message is formed by replacing each {@code %s} placeholder in the template with an
* argument. These are matched by position - the first {@code %s} gets {@code
* errorMessageArgs[0]}, etc. Unmatched arguments will be appended to the formatted message
* in square braces. Unmatched placeholders will be left as-is.
* @param errorMessageArgs the arguments to be substituted into the message template. Arguments
* are converted to strings using {@link String#valueOf(Object)}.
*
* @return the non-null reference that was validated
*
* @throws NullPointerException if {@code reference} is null
*/
public static <T> T checkNotNull(T reference,
@Nullable String errorMessageTemplate,
@Nullable Object... errorMessageArgs) {
if (reference == null) {
// If either of these parameters is null, the right thing happens anyway
NullPointerException nullPointerException = new NullPointerException((format(errorMessageTemplate, errorMessageArgs)));
Crashlytics.logException(nullPointerException);
throw nullPointerException;
}
return reference;
}
/**
* Substitutes each {@code %s} in {@code template} with an argument. These are matched by
* position: the first {@code %s} gets {@code args[0]}, etc. If there are more arguments than
* placeholders, the unmatched arguments will be appended to the end of the formatted message in
* square braces.
*
* @param template a non-null string containing 0 or more {@code %s} placeholders.
* @param args the arguments to be substituted into the message template. Arguments are converted
* to strings using {@link String#valueOf(Object)}. Arguments can be null.
*/
// Note that this is somewhat-improperly used from Verify.java as well.
static String format(String template, @Nullable Object... args) {
template = String.valueOf(template); // null -> "null"
// start substituting the arguments into the '%s' placeholders
StringBuilder builder = new StringBuilder(template.length() + 16 * args.length);
int templateStart = 0;
int i = 0;
while (i < args.length) {
int placeholderStart = template.indexOf("%s", templateStart);
if (placeholderStart == -1) {
break;
}
builder.append(template.substring(templateStart, placeholderStart));
builder.append(args[i++]);
templateStart = placeholderStart + 2;
}
builder.append(template.substring(templateStart));
// if we run out of placeholders, append the extra args in square braces
if (i < args.length) {
builder.append(" [");
builder.append(args[i++]);
while (i < args.length) {
builder.append(", ");
builder.append(args[i++]);
}
builder.append(']');
}
return builder.toString();
}
}