Use cases, contracts, testing

Use case

• enterItem(upc, qty)
• endSale()
• makePayment()

Contract

• UPC is known to the system

• If a new sale, a Sale was created
• If a new sale, the new sale was associated with the POST
• A SalesLineItem was created
• The SalesLineitem was associated with the Sale
• SalesLineItem.quantity was set to quantity
• The SalesLineItem was associated with a ProductSpecification based on UPC match

Collaboration diagram

EnterItem contract

    /**
     * @pre Post.isKnown(upc)
     * @post getSale().getLastLineItem().getQty() == qty
     * @post getSale().getLastLineItem().getSpecification().getUpc() == upc
     */
    public void enterItem(int upc, int qty);

Dependencies

• ProductSpecification does not rely on any other classes. This can be tested first
• ProductCatalog relies on ProductSpecification but nothing else. This can be tested next
• SalesLineItem relies on ProductSpecification. This can be done next
• Sale relies on SalesLineItem and can be done next
• Finally, enterItem for POST can be tested

ProductSpecification contract

public class ProductSpecification {

    /**
     * @pre description != null
     * @post upc == getUpc()
     * @post description.equals(getDescription())
     */
    public ProductSpecification(int upc, String description);

    public int getUpc();

    public String getDescription();
}

ProductSpecification implementation

public class ProductSpecification {

    private String description;
    private int upc;

    /**
     * @pre description != null
     * @post upc == getUpc()
     * @post description.equals(getDescription())
     */
    public ProductSpecification(int upc, String description) {
	this.upc = upc;
	this.description = description;
    }

    public int getUpc() {
	return upc;
    }

    public String getDescription() {
	return description;
    }
}

ProductSpecification tests

test test-1 {constructor} {
    set spec [java::new ProductSpecification 300 "some description"]
    set result [$spec getDescription]
} {some description}

test test-2 {constructor} {
    set spec [java::new ProductSpecification 300 "some description"]
    set result [$spec getUpc]
} {300}

ProductCatalog contract

public class ProductCatalog {

/**
     * @pre isKnown(upc)
     * @post return.getUpc() == upc
     */
    public ProductSpecification getSpecification(int upc);

    public boolean isKnown(int upc);

    /**
     * From manager use case
     * @pre ! isKnown(upc)
     * @post isKnown(upc)
     * @post getSpecification(upc).getUpc() == upc
     * @post getSpecification(upc).getDescription().equals(description)
     */
    public void add(int upc, String description);
}

ProductCatalog implementation

import java.util.HashMap;

public class ProductCatalog {

    private HashMap specs = new HashMap();

    /**
     * @pre isKnown(upc)
     * @post return.getUpc() == upc
     */
    public ProductSpecification getSpecification(int upc) {
	Integer Upc = new Integer(upc);
	return (ProductSpecification) specs.get(Upc);
    }

    public boolean isKnown(int upc) {
	Integer Upc = new Integer(upc);
	return specs.containsKey(Upc);
    }

    /**
     * From manager use case
     * @pre ! isKnown(upc)
     * @post isKnown(upc)
     * @post getSpecification(upc).getUpc() == upc
     * @post getSpecification(upc).getDescription().equals(description)
     */
    public void add(int upc, String description) {
	ProductSpecification spec = new ProductSpecification(upc, description);
	specs.put(new Integer(upc), spec);
    }
}

ProductCatalog tests

############################################
#
# add/isKnown
#

test test-1a {add boundary case, no products} {
    set catalog [java::new ProductCatalog]
    $catalog isKnown 123
} {0}

test test-1b {add boundary case, 1 value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr
    $catalog isKnown 123
} {1}

test test-1c {add boundary case, 1st value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr1
    $catalog add 234 descr2
    $catalog add 345 desrc3
    $catalog isKnown 123
} {1}

test test-1d {add boundary case, 1st value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr1
    $catalog add 234 descr2
    $catalog add 345 desrc3
    $catalog isKnown 123
} {1}

test test-1e {add boundary case, last value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr1
    $catalog add 234 descr2
    $catalog add 345 desrc3
    $catalog isKnown 345
} {1}

test test-1f {add typical case, typical present value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr1
    $catalog add 234 descr2
    $catalog add 345 desrc3
    $catalog add 456 desrc4
    $catalog add 567 desrc5
    $catalog isKnown 345
} {1}

test test-1g {add typical case, typical missing value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr1
    $catalog add 234 descr2
    $catalog add 345 desrc3
    $catalog add 456 desrc4
    $catalog add 567 desrc5
    $catalog isKnown 876
} {0}

########################################################
#
# add/getProductSpec
#

test test-2a {add boundary case, 1 value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr

    set spec [$catalog getSpecification 123]
    set upc [$spec getUpc]
    set descr [$spec getDescription]
    set result "$upc $descr" 
} {123 descr}

test test-2bb {add boundary case, 1st value} {
    set catalog [java::new ProductCatalog]
    $catalog add 123 descr1
    $catalog add 234 descr2
    $catalog add 345 desrc3

    set spec [$catalog getSpecification 123]
    set upc [$spec getUpc]
    set descr [$spec getDescription]
    set result "$upc $descr" 
} {123 descr1}