MRDatabaseContentChecker is a small library to make checking the contents of a database easier and more literate in your tests. It tries to stay out your way and make writing tedious checks simpler and less error prone.

You can test the content of either tables or queries.

MRDatabaseContentChecker requires that you are using FMDB.

You can check either the full content of database tables, or the results of a query (as they're both table-like structures).

The simplest example, using SenTest, is something like the following:

FMDatabase *db = [...];
MRDatabaseContentChecker *dc = [[MRDatabaseContentChecker alloc] init];

NSError *validationError;
NSArray *expectedRows = @[
    @[@"first_name", @"surname"],  // first array is column headers
    @[@"Mike",       @"Rhodes"],   // expected data starts in row 2
    @[@"John",       @"Smith"]     // and continues...
];
STAssertTrue([dc checkDatabase:db
                         table:@"users"
                       hasRows:expectedRows
                         error:&validationError],
             [dc formattedErrors:validationError]);

Essentially:

1. Create your expected values array. This is an array of arrays. The first array always contains the column headers you want to check. The following rows define the data you expect to find.
2. Call -checkDatabase:table:hasRows:error: in a testing macro.
3. If that returns NO, use the -formattedErrors helper to print the failures.

The above example can be rewritten to use a query rather than a table name:

FMDatabase *db = [...];
MRDatabaseContentChecker *dc = [[MRDatabaseContentChecker alloc] init];

NSError *validationError;
NSArray *expectedRows = @[  /* as before */  ];
STAssertTrue([dc checkDatabase:db
                         query:@"select first_name, surname from users;"
                       hasRows:expectedRows
                         error:&validationError],
             [dc formattedErrors:validationError]);

At the moment, there's no support for placeholders; you control the SQL you're generating in your tests. Or, if not, feel free to open a PR as I'm not in the slightest averse to including further features.

• The table-checking variant relies on the "undefined" ordering that SQLite returns rows in. Right now, if this doesn't work, using the query variant is neccessary to allow an ORDER BY clause to be included.
• There is no limit enforced on the number of errors reported. This may be a problem if there are millions of errors as every error has an entry in the error object passed out of the method.

-checkDatabase:table:hasRows:error: and -checkDatabase:query:hasRows:error: check:

• Each expected value matches is corresponding item in the result set.
• There are the same number of results as expected.

As shown above, expected values are passed as an array of arrays. Each expected value is check against its corresponding entry in the result set based on its type. The allowed types are:

NSString

NSString objects are checked using -isEqual.

NSNumber

NSNumber objects are checked using -isEqual against -longLongIntForColumn values from the database.

BOOL (boxed)

As a boxed BOOL is an NSNumber, see NSNumber.

NSData

NSData objects are checked using -isEqual against -dataForColumn value from database.

NSRegularExpression

This check passes if the return value from -numberOfMatchesInString:options:error: returns one or more matches.

[NSNull null]

This check checks [NSNull null] against the value returned for the column by -objectForColumnName:.

Using an unsupported type (or a class that isn't a subclass of a supported type) will result in a failure checking the value.

You can pass different datatypes for a given column's expected values:

expectedRows = @[
    @[@"name",        @"github_username", @"age"],
    @[@"Mike Rhodes", @"mikerhodes",      @30],
    @[@"John Smith",  [NSNull null],      @27]
];

MRDatabaseContentChecker depends on:

• FMDB

MRDatabaseContentChecker is available through CocoaPods, to install it add the following line to your Podfile:

pod "MRDatabaseContentChecker"

Michael Rhodes, [email protected]

MRDatabaseContentChecker is available under the Apache v2 license. See the LICENSE file for more info.