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Integration Testing Path Based Chapter 13 Call graph based - - PowerPoint PPT Presentation
Integration Testing Path Based Chapter 13 Call graph based - - PowerPoint PPT Presentation
Integration Testing Path Based Chapter 13 Call graph based integration Use the call graph instead of the decomposition tree What is a call graph? IntP2 Call graph definition Is a directed, labeled graph Vertices are methods
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IntP–3
Call graph definition
Is a directed, labeled graph
Vertices are methods A directed edge joins calling vertex to the called vertex Adjacency matrix is also used Does not scale well, although some insights are useful
Nodes of high degree are critical
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IntP–4
SATM call graph example
Look at adjacency matrix p204
1 5 7 20 21 9 10 12 11 16 17 18 19 22 23 24 25 26 14 2 3 6 8 4 13 15 27
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IntP–5
Call graph integration strategies
What types of integration strategies are used?
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IntP–6
Call graph integration strategies – 2
What types of integration strategies are used?
Pair-wise Integration Testing Neighborhood Integration Testing
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IntP–7
Pair-wise integration
What is pair-wise integration
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IntP–8
Some Pair-wise Integration Sessions
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Pair-wise integration session example
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IntP–9
Pair-wise integration – 2
The idea behind Pair-Wise integration testing
Eliminate need for developing stubs / drivers Use actual code instead of stubs/drivers
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IntP–10
Pair-wise integration – 3
In order not to deteriorate the process to a big-bang strategy
Restrict a testing session to just a pair of units in the call
graph
Results in one integration test session for each edge in the
call graph
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IntP–11
Neighbourhood integration
What is neighbourhood integration?
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IntP–12
Neighbourhood integration example
Neighbourhoods for nodes 16 & 26
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IntP–13
Neighbourhood integration – 2
The neighbourhood of a node in a graph
The set of nodes that are one edge away from the given
node
In a directed graph
All the immediate predecessor nodes and all the immediate
successor nodes of a given node
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IntP–14
Neighbourhood integration – 3
Neighborhood integration testing
Reduces the number of test sessions
#Neighborhoods = #interior_nodes + #source_nodes
Fault isolation is difficult
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IntP–15
Pros of call-graph integration
What are the pros of call-graph integration?
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IntP–16
Pros of call-graph integration – 2
What are the pros of call-graph integration?
Reduces the need for drivers and stubs
Relative to functional decomposition integration
Neighborhoods can be combined to create “villages” Closer to a build sequence
Well suited to devising a sequence of builds with which
to implement a system
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IntP–17
Cons of call-graph integration
What are the cons of call-graph integration?
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IntP–18
Cons of call-graph integration – 2
What are the cons of call-graph integration?
Suffers from fault isolation problems
Especially for large neighborhoods
Redundancy
Nodes can appear in several neighborhoods
Assumes that correct behaviour follows from correct units
and correct interfaces
Not always the case
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IntP–19
Path-based integration
What is path-based integration?
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IntP–20
Path-Based Integration – 2
Motivation
Combine structural and behavioral type of testing for
integration testing as we did for unit testing
Interface-based testing is structural while interaction-based
testing is behavioral
Basic idea
Focus on interactions among system units Rather than merely to test interfaces among separately
developed and tested units
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IntP–21
Source node
What is a source node?
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IntP–22
Source node – 2
What is a source node?
A program statement fragment at which program execution
begins or resumes.
For example the first “begin” statement in a program. Nodes immediately after nodes that transfer control to
- ther units.
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IntP–23
Sink node
What is a sink node?
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IntP–24
Sink node
What is a sink node?
A statement fragment at which program execution
terminates
The final “end” in a program as well as statements that
transfer control to other units
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IntP–25
Module execution path (MEP)
What is a module execution path?
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IntP–26
Module execution path (MEP) – 2
What is a module execution path?
A sequence of statements within a module that
Begins with a source node Ends with a sink node With no intervening sink nodes
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IntP–27
Message
What is a message?
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IntP–28
Message – 2
What is a message?
A programming language mechanism by which one unit
transfers control to another unit
Usually interpreted as subroutine / function invocations The unit which receives the message always returns control
to the message source
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IntP–29
MM-path
What is an MM-path?
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IntP–30
MM-path – 2
What is an MM-path?
A module to module path
An interleaved sequence of module execution paths and
messages
Used to describes sequences of module execution paths
that include transfers of control among separate units
MM-paths always represent feasible execution paths, and
these paths cross unit boundaries
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IntP–31
1 2 3 4 5 6
A B
1 2 3 4
C
1 2 5 3 4
MM-path example
Source nodes
Sink nodes MM-path MEP(C,1) = <1, 2, 4, 5> MEP(C,2) = <1, 3, 4, 5> MEP(B,1) = <1, 2> MEP(B,2) = <3, 4> MEP(A,1) = <1, 2, 3, 6> MEP(A,2) = <1, 2, 4> MEP(A,3) = <5, 6>
Module Execution Paths
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IntP–32
MEPs and DD-paths
What is the correspondence between MEPs and a DD-
paths?
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IntP–33
MEPs and DD-paths – 2
What is the correspondence between MEPs and a DD-
paths?
There is no correspondence between MM execution paths
and DD-paths
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IntP–34
MEPs and slices
What is the correspondence between MEPs and slices?
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IntP–35
MEPs and slices – 2
What is the correspondence between MEPs and slices?
There is no correspondence but there is an analog
The intersection of a module execution path with a unit
is the analog of a slice with respect to the MM-path function
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IntP–36
MM-path graph
What is an MM-path graph?
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IntP–37
MM-path graph – 2
What is an MM-path graph?
Given a set of units their MM-path graph is the directed
graph in which
Nodes are module execution paths Edges correspond to messages and returns from one
unit to another
The definition is with respect to a set of units
It directly supports composition of units and
composition-based integration testing
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IntP–38
Solid lines indicate messages (calls) Dashed lines indicate returns from calls
MM-path graph example
MEP(C,2) MEP(A,1) MEP(A,2) MEP(A,3) MEP(B,1) MEP(C,1) MEP(B,2)
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IntP–39
MM-path guidelines
How long, or deep, is an MM-path? What determines the end
points?
Quiescence points are natural endpoints for MM-paths
Message quiescence Data quiescence
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IntP–40
Message quiescence
Occurs when a unit that sends no messages is reached
Module C in the example
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IntP–41
Data quiescence
Occurs when a sequence of processing ends in the creation
- f stored data that is not immediately used
The causal path Data A has no quiescence The non-causal path D1 and D2 is quiescent at the node P-1
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IntP–42
MM-path metric
What is the minimum number of MM-paths that are
sufficient to test a system?
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IntP–43
MM-Path metric – 2
What is the minimum number of MM-paths that are
sufficient to test a system?
Should cover all source-to-sink paths in the set of units
What about loops? How should they be treated?
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IntP–44
MM-Path metric – 3
What about loops? How should they be treated?
Use condensation graphs to get directed acyclic graphs
Avoids an excessive number of paths
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IntP–45
Pros of path-based integration
Benefits of hybrid of functional and structural testing
Functional – represent actions with input and output Structural – how they are identified
Avoids pitfall of structural testing
Unimplemented behaviours cannot be tested
Fairly seamless union with system testing
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IntP–46
Pros of path-based integration – 2
Path-based integration is closely coupled with actual system
behaviour
Works well with OO testing
No need for stub and driver development
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IntP–47
Cons of path-based integration
There is a significant effort involved in identifying MM-paths
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IntP–48
MM-path compared to other methods
Strategy Ability to test interfaces Ability to test co-functionality Fault isolation resolution Functional decomposition Acceptable, can be deceptive Limited to pairs
- f units
Good to faulty unit Call-graph Acceptable Limited to pairs
- f units