- 117 Views
- Uploaded on
- Presentation posted in: General

A Review of Graphs for Testing

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

A Review of Graphs for Testing

- A directed graph G(V,E)
- A finite V = {n1, n2, …, nm} of nodes
- A finite set E = {e1, e2, …, ep} of edges
- Each edge ek = {ni, nj} is an ordered pair (start and end nodes)
- V = {n1, n2, n3}
- E = {e1, e2, e3} = {(n1,2), (n2,n3), (n2,n4)}

e1

e2

n1

n2

n3

e3

n4

- Indegree (ni): the number of distinct edges that have ni as a terminal node
- Outdegree (ni): the number of distinct edges that have ni as starting node
- Source node: a node with indegree={}
- Sink node: a node with outdegree = {}
- Transfer node: a node with indegree !={} and outdegree != {}

- Directed path: a sequence of edges such that for any adjacent pairs of ei, ej, the terminal node of ei is the start node of ej
- Connectedness: for two odes ni, nj
- 0-connected: iff there is no path between ni, nj
- 2-connected: iff there is a path between ni, nj
- 3-connected: iff there is a path from ni to nj and a path from nj to ni

- Strongly connected graph: all pairs of nodes are 3-connected

- Given a program in an imperative language, its graph is a directed graph in which noes are either entire statements or fragments of a statement and edges represent flow of control

- Given a program in an imperative language, its graph is a directed graph in which noes are either entire statements or fragments of a statement and edges represent flow of control

- The cyclomatic number of a graph G is given by
- V(G) = e – n + 2, where
- e is the number of edges in G
- n is the number of nodes in G

- Cyclomatic complexity pertains to both ordinary and directed graphs
- V(G) is sometimes called McCabe Complexity after Thomas McCabe

- Used for testing (identifying the number of independent paths) and design (reduce complexity)
- It gives the number of independent paths from in a program (also called the basis path)
- It provides the degree of complexity