Sequence Step

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A Sequence Step is an element of a Test Sequence that references a Sequenced Test Object and defines occurrence-specific information and permitted progression.

A Test Sequence is a specialization of Sequence. Each Sequence Step identifies one position within the ordering or directed progression established by the Test Sequence.

A Sequence Step references one Sequenced Test Object, such as a:

• Test Set
• Test Case
• Test Step
• Test Executable

A Sequence Step can identify:

• Its identity
• Its name
• Its description
• Its position within the Test Sequence
• Its referenced Sequenced Test Object
• Its applicable Test Argument Values
• Its applicable Expected Results
• Its applicable Test Items
• Its applicable Starting Conditions
• Its applicable Timing Conditions
• Its required prior conditions
• Its completion condition
• Its failure condition
• Its Timeout
• Its permitted following Sequence Steps
• Its progression conditions
• Its alternative progression
• Its error-handling progression
• Its applicable Governance Policies
• Its Provenance
• Its Traceability

A Sequence Step can supply occurrence-specific Test Argument Values to the referenced Sequenced Test Object.

A Sequence Step can also identify one or more permitted following Sequence Steps. Progression can depend on:

• Completion of the current Sequence Step
• A Test Result
• A Verdict
• A measured value
• An observed event
• A state
• A Timeout
• An error
• Another defined progression condition

The Sequence Step defines permitted progression. The applicable Execution Path identifies the progression that actually occurs during Test Execution.

element of a Test Sequence that references a Sequenced Test Object and defines occurrence-specific information and permitted progression

Adapted from:

• OMG Test Information Interchange Format (TestIF), Version 1.0 Beta 3, Section 7.3.4, SequenceStep
• Sequence
• Test Sequence
• Sequenced Test Object
• Test Argument Value
• Execution Path
• DIDO Reference Implementation Conceptual Model
• DIDO-TE draft Requirements Register

OMG TestIF defines SequenceStep as a directed-graph node contained within a TestSequence. The SequenceStep references the SequencedTestObject represented at that position and identifies the SequenceSteps that can follow it.

OMG TestIF also permits a SequenceStep to provide ArgumentValues for the input variables of its referenced SequencedTestObject.

This definition preserves those characteristics while:

• Defining Sequence Step as an element of a Test Sequence
• Relating Test Sequence to the general concept of Sequence
• Separating permitted progression from the Execution Path that actually occurs
• Remaining independent of a particular graph-storage or implementation technology

A Sequence Step differs from a Sequence:

• A Sequence defines an ordered or directed arrangement of elements and the progression relationships among them
• A Sequence Step is one element within a Test Sequence

A Sequence Step differs from a Test Sequence:

• A Test Sequence defines the overall ordering and permitted progression
• A Sequence Step identifies one position and defined occurrence within that progression

A Sequence Step differs from a Test Step:

• A Test Step specifies a reusable test action or Validation
• A Sequence Step identifies an occurrence of a Sequenced Test Object within a Test Sequence

A Sequence Step can reference a Test Step, but the Sequence Step and Test Step remain separate TestIF objects.

The same Test Step can occur at multiple positions within one Test Sequence. Each occurrence uses a separate Sequence Step.

A Sequence Step differs from a Sequenced Test Object:

• A Sequenced Test Object defines reusable test content
• A Sequence Step identifies how that content participates at one position within a Test Sequence

The same Sequenced Test Object can participate in:

• Multiple Test Sequences
• Multiple positions within one Test Sequence
• Multiple branches within one Test Sequence
• Multiple Test Runs

Each Sequence Step can provide different:

• Test Argument Values
• Expected Results
• Starting Conditions
• Timing Conditions
• Progression conditions
• Error-handling progression
• Other occurrence-specific information

A Sequence Step does not copy or redefine the referenced Sequenced Test Object. It supplies or references the information needed to use that object at a particular position.

A Sequence Step differs from an Execution Path:

• A Sequence Step defines a potential occurrence and permitted progression within a Test Sequence
• An Execution Path identifies which Sequence Steps occurred and how progression actually proceeded during Test Execution

A Sequence Step can remain unperformed when:

• Test Execution follows another conditional branch
• A preceding Sequence Step fails
• A Timeout causes error-handling progression
• Test Execution terminates before reaching the Sequence Step
• An authorized Actor cancels the Test Run

Multiple initial Sequence Steps can define parallel starting paths.

Multiple following Sequence Steps can define:

• Parallel progression
• Conditional progression
• Alternative progression
• Error-handling progression

The Test Sequence provides sufficient progression information to distinguish parallel progression from conditional or alternative progression.

A Test Result can reference both:

• The Sequenced Test Object whose performance produced the outcome
• The Sequence Step that identifies the particular occurrence of that Sequenced Test Object

This dual reference distinguishes Test Results produced by separate occurrences of the same Sequenced Test Object.

A reusable Test Step submits a proposed transaction to a Node.

A Test Sequence contains three Sequence Steps that reference the same Test Step:

• Sequence Step SS-01 supplies the Endpoint and identity of Node A
• Sequence Step SS-02 supplies the Endpoint and identity of Node B
• Sequence Step SS-03 supplies the Endpoint and identity of Node C

Each Sequence Step supplies occurrence-specific Test Argument Values while reusing the same Test Step.

During Test Execution, the Test Run records:

• Whether each Sequence Step occurred
• The Test Argument Values used for each occurrence
• The Starting Conditions applicable to each occurrence
• The Timing Conditions applicable to each occurrence
• The start time and completion time of each occurrence
• The Test Result produced by each occurrence
• The Verdict assigned to each Test Result
• The Execution Path followed
• The supporting Evidence

Although all three Sequence Steps reference the same Test Step, each Test Result remains traceable to the particular Node and Sequence Step that produced it.