<?php
/**
 * PHPUnit tests for MathTexvc.
 *
 * @group Extensions
 * @group Math
 */

/**
 * @covers MathTexvc
 */
class MathTexvcTest extends MediaWikiTestCase {

	/**
	 * Tests behavior of render() upon a cache hit.
	 * If the rendered object exists in the database cache, MathTexvc
	 * just generates HTML from it, and skips shelling out to texvc
	 * entirely.
	 * @covers MathTexvc::render
	 */
	function testRenderCacheHit() {
		global $wgMathCheckFiles;

		// Disable file checks. (This is permissable, because PHPUnit
		// will backup / restore global state on test setup / teardown.)
		$wgMathCheckFiles = false;

		// Create a MathTexvc mock, replacing methods 'readFromDatabase',
		// 'callTexvc', and 'doHTMLRender' with test doubles.
		$texvc = $this->getMockBuilder( 'MathTexvc' )
			->setMethods( array( 'readFromDatabase', 'callTexvc', 'doHTMLRender' ) )
			->disableOriginalConstructor()
			->getMock();

		// When we call render() below, MathTexvc will ...

		// ... first check if the item exists in the database cache:
		$texvc->expects( $this->once() )
			->method( 'readFromDatabase' )
			->with()
			->will( $this->returnValue( true ) );

		// ... if cache lookup succeeded, it won't shell out to texvc:
		$texvc->expects( $this->never() )
			->method( 'callTexvc' );

		// ... instead, MathTexvc will skip to HTML generation:
		$texvc->expects( $this->once() )
			->method( 'doHTMLRender' );

		$texvc->render();
	}

	/**
	 * Test behavior of render() upon cache miss.
	 * If the rendered object is not in the cache, MathTexvc will shell
	 * out to texvc to generate it. If texvc succeeds, it'll use the
	 * result to generate HTML.
	 * @covers MathTexvc::render
	 */
	function testRenderCacheMiss() {
		$texvc = $this->getMockBuilder( 'MathTexvc' )
			->setMethods( array( 'readCache', 'callTexvc', 'doHTMLRender' ) )
			->disableOriginalConstructor()
			->getMock();

		// When we call render() below, MathTexvc will ...

		// ... first look up the item in cache:
		$texvc->expects( $this->once() )
			->method( 'readCache' )
			->will( $this->returnValue( false ) );

		// ... on cache miss, MathTexvc will shell out to texvc:
		$texvc->expects( $this->once() )
			->method( 'callTexvc' )
			->will( $this->returnValue( MW_TEXVC_SUCCESS ) );

		// ... if texvc succeeds, MathTexvc will generate HTML:
		$texvc->expects( $this->once() )
			->method( 'doHTMLRender' );

		$texvc->render();
	}

	/**
	 * Test behavior of render() when texvc fails.
	 * If texvc returns a value other than MW_TEXVC_SUCCESS, render()
	 * returns the error object and does not attempt to generate HTML.
	 * @covers MathTexvc::render
	 */
	function testRenderTexvcFailure() {
		$texvc = $this->getMockBuilder( 'MathTexvc' )
			->setMethods( array( 'readCache', 'callTexvc', 'doHTMLRender' ) )
			->disableOriginalConstructor()
			->getMock();

		// When we call render() below, MathTexvc will ...

		// ... first look up the item in cache:
		$texvc->expects( $this->any() )
			->method( 'readCache' )
			->will( $this->returnValue( false ) );

		// ... on cache miss, shell out to texvc:
		$texvc->expects( $this->once() )
			->method( 'callTexvc' )
			->will( $this->returnValue( 'error' ) );

		// ... if texvc fails, render() will not generate HTML:
		$texvc->expects( $this->never() )
			->method( 'doHTMLRender' );

		// ... it will return the error result instead:
		$this->assertEquals( $texvc->render(), 'error' );
	}
}