Jasmine-where NPM

DEPRECATION NOTICE 7 JAN 2014

jasmine-where has been superseded by where.js

jasmine-where

Provides a where() clause for data-table support to the Jasmine BDD test framework, similar to Cucumber's scenario-outline Examples or Spock's where blocks.

Partly inspired by:

JP Castro's (@jphpsf) DRYing Up Your JavaScript Jasmine Tests With the Data Provider Pattern
Richard Rodger's mstring

install

npm install jasmine-where

git clone https://github.com/dfkaye/jasmine-where.git

important

Including or requiring jasmine-where adds a where() method to the global namespace, for example:

require('jasmine-where');

where === global.where === jasmine.getEnv().where;

<script -- jasmine 1 or 2 scripts first -->
<script src="../jasmine-where.js"></script>

where === window.where === jasmine.getEnv().where;

justify

Easier to modify this

it('description', function () {

  where(function(){/*** 
      a  |  b  |  c
      1  |  2  |  2
      4  |  3  |  4
      6  |  6  |  6
    ***/
    
    expect(a + b)).toBe(c);
  });
  
});

than this:

it('description', function () {

  [[1, 2, 2],
   [4, 3, 4],
   [6, 6, 6]].forEach(function(row, r, rows) {
           
    expect(Number(row[0]) + Number(row[1])).toBe(Number(row[2]));
  });
  
});

story

Borrowing from Richard Rodger's mstring, where() accepts a function and inspects its string value, converts the triple- commented data-table into an array of values, uses the labels as variables or symbols in a new Function().

Each where() clause works best with only one expectation clause at the moment (still debating whether it's worth supporting multiple expects in a single where()).

format

Data tables must contain at least two rows, the first row containing symbols to be used as variables in the expectation, whereas the remaining rows must contain data for each symbol.

For example:

it('should pass with correct data and expectation', function () {
  where(function(){/***
     a | b | c
     1 | 2 | 2
     4 | 3 | 4
     6 | 6 | 6
    ***/
    expect(Math.max(a, b)).toBe(c);
  });
});

Tables may also contain left and right borders, similar to Cucumber and Fit:

it('should pass with left and right table borders', function () {
  where(function(){/***
    | a | b | c |
    | 1 | 2 | 2 |
    | 4 | 3 | 4 |
    | 6 | 6 | 6 |
    ***/
    expect(Math.max(a, b)).toBe(c);
  });
});

Numeric data is automatically coerced to Number type

Supports Math.max(a, b) to avoid re-typing Math.max(Number(a), Number(b)).

Everything can use toBe() (strict equality) - no need to rely on toMatch().

However, where Math is involved there is usually an octal, signed, comma, or precision bug waiting. All but precision are handled automatically; however, you can get precision into your tests by adding another column, as seen in the test created to verify numeric conversions work:

where(function(){/***

        a     |    b     |    c     |  p
        
        0     |    1     |    1     |  1
        0.0   |    1.0   |    1     |  1
       -1     |   +1     |    0     |  1
       +1.1   |   -1.2   |   -0.1   |  2
       08     |   08     |   16     |  2
        6     |    4     |   10.0   |  3
        8.030 |   -2.045 |    5.985 |  4
    1,000.67  | 1345     | 2345.67  |  6
    
  ***/
  
  // using precisions for famous 5.985 vs 5.98499999999999999999999999 bugz
  var s = (a + b).toPrecision(p) // toPrecision() returns a string
  expect(+s).toBe(c) // but prefixed '+' uses implicit conversion to number.
});

output

A passing where() clause has no effect on the usual jasmine output.

When an expectation fails, the data-table labels plus the row of values for the current expectation are added to the current failing item. Every failed expectation in a where() clause will appear as:

 [a | b | c] : 
 [1 | 2 | x] (Expected 2 to be 'x'.)

inspect return values

You can capture the generated data table, including the labels, as the return value of the where clause for post-where assertions:

it('returns data', function () {
  
    var results = where(function(){/***
    
        a  |  b  |  c
        1  |  1  |  1
        1  |  2  |  two
        3  |  2  |  3
        5  |  3  |  5.01
        
      ***/
      
      // within where
      expect(Math.max(a, b)).toBe(c);
    });
    
    
    // inspect results returned by where()
    expect(results[2][2]).toBe('two');
});

jasmine-intercept test dependency

In working this out, I found I needed a way to intercept the results in where tests that were expected to fail. I've worked out jasmine-intercept to handle that. It is included in the node_modules directory of this repo (if you're viewing on github).

jasmine versions supported

Current implementation runs in both jasmine 1.3.1 and jasmine 2.0.0-rc3.

jasmine-node

Using jasmine-node which uses jasmine-1.3.1 internally. Run that with

jasmine-node --verbose ./test/node-suite.js

or simply

npm test

rawgit test page

The jasmine2 browser test page is viewable on rawgit.

testem

Using Toby Ho's MAGNIFICENT testemjs to drive tests in multiple browsers for jasmine-2.0.0 (see how to hack testem for jasmine 2), as well as jasmine-node. The testem.json file uses the standalone test page above, and also uses a custom launcher for jasmine-node (v 1.3.1).

In addition, the following command uses a custom launcher for jasmine-node in testem: