mlx.traceability 3.4.2

Sphinx traceability extension (Melexis fork)

Sphinx Traceability plugin

Sphinx plugin that allows defining documentation items and relations between those items. Can be used as a requirements management tool for e.g. ISO26262 projects.

Contents

• Goal

• Installing

• Configuration

  • Valid attributes

  • Stringification of attributes

  • Valid relationships

  • Stringification of relationships

  • External relationship to URL translation

  • Rendering of relationships per documentation object

  • Rendering of attributes per documentation object

  • Ability to collapse the list of relationships and attributes per documentation object

  • No captions

  • Export

  • Callback per item (advanced)

  • Custom colors for linked items

  • Default config

• Usage

  • Required sphinx options

  • Defining documentation items

  • Adding relations outside of the item definitions

  • Adding description to attributes

  • Manual link to documentation items

  • Flat list of documentation items

  • Matrix with attributes of documentation items

  • Traceability matrix of documentation items

  • 2D-matrix of documentation items

  • Documentation items tree-view

  • Pie chart of documentation items

  • Retrieving checklist values from GitLab/GitHub (advanced)

• Process

Goal

Define documentation items which can be linked to each other. E.g. define requirements which can be derived from other requirements, or linked to design items and test case descriptions.

Every item is an object in the documentation, which can have different relations to other objects in the documentation. Documentation objects can be spread in different documents.

Two kinds of relationships exist:

• Internal relationships: Relationships between objects of the documentation (items). Once a (forward) relationship from item A to item B is defined, the reverse relationship from item B to item A is automatically generated by the plugin.

• External relationships: Relationship from an object of the documentation (item), to an external reference (url of e.g. an external tool). As no item B exists, the reverse relationship is also not defined.

Relationships are configurable.

The plugin can generate

• rendered versions of the defined documentation objects

• flat lists of documentation objects

• traceability matrices between objects

Installing

pip3 install mlx.traceability

Configuration

The conf.py file contains the documentation configuration for your project. This file needs to be equipped in order to configure the traceability plugin.

First the plugin needs to be enabled in the extensions variable:

extensions = [
    'mlx.traceability',
    ...
]

Second the path to the static javascript assets needs to be added to the sphinx html_static_path variable.

import os
import mlx.traceability

html_static_path = [os.path.join(os.path.dirname(mlx.traceability.__file__), 'assets')]

Valid attributes

Python variable traceability_attributes can be defined in order to override the default configuration of the traceability plugin. It is a set of attribute pairs: the key is the name of the attribute (can only be lowercase), while the value holds the regular expression to which the attribute-value should comply.

Example of attributes and their regular expression:

traceability_attributes = {
    'value': '^.*$',
    'asil': '^(QM|[ABCD])$',
}

Stringification of attributes

Python variable traceability_attribute_to_string can be defined in order to override the default configuration of the traceability plugin. It is a set of attribute stringifications: the key is the name of the attribute, while the value holds the string representation (as to be rendered in html) of the attribute name.

Example of attribute stringification:

traceability_relationship_to_string = {
    'value': 'Value',
    'asil': 'ASIL',
}

Valid relationships

Python variable traceability_relationsips can be defined in order to override the default configuration of the traceability plugin. It is a set of relationship pairs: the key is the name of the forward relationship, while the value holds the name of the corresponding reverse relationship. Both can only be lowercase.

Relationships with prefix ext_ are treated in a different way: they are handled as external relationships and don’t need a reverse relationship.

Example of internal and external relationship pairs:

traceability_relationships = {
    'validates': 'validated_by',
    'ext_polarion_reference': ''
}

Stringification of relationships

Python variable traceability_relationship_to_string can be defined in order to override the default configuration of the traceability plugin. It is a set of relationship stringifications: the key is the name of the (forward or reverse) relationship, while the value holds the string representation (as to be rendered in html) of the relationship.

Example of internal and external relationship stringification:

traceability_relationship_to_string = {
    'validates': 'Validates',
    'validated_by': 'Validated by',
    'ext_polarion_reference': 'Polarion reference'
}

External relationship to URL translation

External relationships need to be translated to URL’s while rendering. For each defined external relationship, an entry in the Python set named traceability_external_relationship_to_url is needed. The URL generation is templated using the fieldx keyword, where x is a number incrementing from 1 onwards for each value in the URL that needs to be replaced.

Example configuration of URL translation of external relationship using 2 fields:

traceability_external_relationship_to_url = {
    'ext_polarion_reference': 'https://melexis.polarion.com/polarion/#/project/field1/workitem?id=field2',
}

Rendering of relationships per documentation object

When rendering the documentation objects, the user has the option to include/exclude the rendering of the relationships to other documentation objects. This can be done through the Python variable traceability_render_relationship_per_item which is boolean: a value of True will enable rendering of relationships per documentation object, while a value of False will disable this rendering.

Example configuration of enable rendering relationships per item:

traceability_render_relationship_per_item = True

Rendering of attributes per documentation object

The rendering of attributes of documentation objects can be controlled through the boolean variable traceability_render_attributes_per_item: rendering of attributes is enabled by setting it to True (the default) while a value of False will prevent the attribute list from being rendered.

Example configuration of disabling per item attribute rendering:

traceability_render_attributes_per_item = False

Ability to collapse the list of relationships and attributes per documentation object

A button is added to each documentation object that has rendered relationships and/or attributes to be able to show and hide these traceability links. The boolean configuration variable traceability_collapse_links allows selecting between hiding and showing the list of links for all items on page load: setting its value to True results in the list of links being hidden (collapsed) on page load, while a value of False results in the list being shown (uncollapsed)(the default).

Example configuration of hiding the traceability links on page load:

traceability_collapse_links = True

No captions

By default, the output will contain hyperlinks to all related items. By default, the caption for the target item is displayed for each of the related items. The captions can be omitted at configuration level (see this section) and at directive level (see e.g. traceability_usage_item_matrix).

No captions for item

Example configuration of disabling the rendering of captions on item:

traceability_item_no_captions = True

No captions for item-list

Example configuration of disabling the rendering of captions on item-list:

traceability_list_no_captions = True

No captions for item-matrix

Example configuration of disabling the rendering of captions on item-matrix:

traceability_matrix_no_captions = True

No captions for item-attributes-matrix

Example configuration of disabling the rendering of captions on item-attributes-matrix:

traceability_attributes_matrix_no_captions = True

No captions for item-tree

Example configuration of disabling the rendering of captions on item-tree:

traceability_tree_no_captions = True

Export

The plugin allows exporting the documentation items.

Export to JSON

As a preliminary test feature, the plugin allows to export the documentation items to a JSON database. The feature can be enabled by setting the configuration to your JSON-file to export to. Note, the JSON-file is overwritten (not appended) on every build of the documentation.

traceability_json_export_path = '/path/to/your/database.json'

As a preliminary feature, the database only contains per documentation item:

• the id,

• the caption,

• the document name and line number,

• the relations to other items.

The actual content (RST content with images, formulas, etc) of the item is currently not stored.

Note

Requires sphinx >= 1.6.0

Callback per item (advanced)

The plugin allows parsing and modifying documentation objects ‘behind the scenes’ using a callback. The callback has this prototype:

def traceability_my_callback_per_item(name, all_items):
    '''
    Custom callback on items

    :param name: Name (id) of the item currently being parsed
    :param all_items: Set of all items that are parsed so far
    '''
    return

The callback is executed while parsing the documentation item from your rst-file. Note that not all items are available at the time this callback executes, the all_items parameter is a growing set of documentation objects.

Example of no callback per item:

traceability_callback_per_item = None

Custom colors for linked items

The plugin allows customization of the colors of traceable items in order to easily recognize the type of item which is linked to. A dictionary in the configuration file defines the regexp, which is used to match item IDs, as key and a tuple of 1-3 color defining strings as value. The first color is used for the default hyperlink state, the second color is used for the hover and active states, and the third color is used to override the default color of the visted state. Leaving a color empty results in the use of the default html style. The top regexp has the highest priority. To support Python versions lower than 3.7, we use an OrderedDict to have a deterministic order for prioritizing regexes.

traceability_hyperlink_colors = OrderedDict([
    (r'^(RQT|r[\d]+', ('#7F00FF', '#b369ff')),
    (r'^[IU]TEST_REP', ('rgba(255, 0, 0, 1)', 'rgba(255, 0, 0, 0.7)', 'rgb(200, 0, 0)')),
    (r'^[IU]TEST', ('goldenrod', 'hsl(43, 62%, 58%)', 'darkgoldenrod')),
    (r'^SYS_', ('', 'springgreen', '')),
    (r'^SRS_', ('', 'orange', '')),
])

Default config

The plugin itself holds a default config that can be used for any traceability documenting project:

traceability_callback_per_item = None
traceability_attributes = {
    'value': '^.*$',
    'asil': '^(QM|[ABCD])$',
    'aspice': '^[123]$',
    'status': '^.*$',
    'result': '(?i)^(pass|fail|error)$'
}
traceability_attribute_to_string = {
    'value': 'Value',
    'asil': 'ASIL',
    'aspice': 'ASPICE',
    'status': 'Status'
}
traceability_relationships = {
    'fulfills': 'fulfilled_by',
    'depends_on': 'impacts_on',
    'implements': 'implemented_by',
    'realizes': 'realized_by',
    'validates': 'validated_by',
    'trace': 'backtrace',
    'ext_toolname': ''
}
traceability_relationship_to_string = {
    'fulfills': 'Fulfills',
    'fulfilled_by': 'Fulfilled by',
    'depends_on': 'Depends on',
    'impacts_on': 'Impacts on',
    'implements': 'Implements',
    'implemented_by': 'Implemented by',
    'realizes': 'Realizes',
    'realized_by': 'Realized by',
    'validates': 'Validates',
    'validated_by': 'Validated by',
    'trace': 'Traces',
    'backtrace': 'Back traces',
    'ext_toolname': 'Reference to toolname'
}
traceability_external_relationship_to_url = {
    'ext_toolname': 'http://toolname.company.com/field1/workitem?field2'
}
traceability_render_relationship_per_item = False

This default configuration, which is built into the plugin, can be overridden through the conf.py of your project.

For Melexis.SWCC silicon projects, the SWCC process holds a default configuration in the config/traceability_config.py file. For each of the above configuration variables, the default configuration file holds a variable with swcc_ prefix. Taking the default configuration is as easy as assiging the above configuration value with the swcc_ variable. Overriding a configuration is as easy as assigning your own values to a configuration value.

Example of accepting default configuration for relationships, while disabling (override) rendering of relationships per documentation object:

sys.path.insert(0, os.path.abspath('<path_to_process_submodule>/config'))

from traceability_config import swcc_traceability_attributes
from traceability_config import swcc_traceability_relationships
from traceability_config import swcc_traceability_relationship_to_string

traceability_attributes = swcc_traceability_attributes
traceability_relationships = swcc_traceability_relationships
traceability_relationship_to_string = swcc_traceability_relationship_to_string
traceability_render_relationship_per_item = False

Usage

Required sphinx options

By default, sphinx (sphinx-build) performs an incremental build: it only parses the changed files and generates new output for changed files. As this plugin generates automatic reverse relations, the incremental build option of sphinx needs to be disabled. This can be done using the -E option:

sphinx-build -E <other_options>

Rationale:

The plugin allows linking documentation items through relations. If a forward relation from item-A (in document-a.rst) to item-B (in document-b.rst) is created, the reverse relations from item-B to item-A is automatically created. With incremental builds, documents only get re-generated when they are changed. This means the automatic reverse relation cannot be created if that document-B was not touched. By disabling incremental builds, it is made sure every document is updated (with automatic reverse relations) on every re-build.

The plugin assumes incremental builds are disabled, as this makes the implementation of the plugin much easier.

Defining documentation items

Documentation items can be defined using the item directive, specifying:

• the name (id) of the documentation item

• caption or short description of the documentation item

• attributes for the documentation item

• internal/external relationships to other documentation items (details in next paragraph)

• content of documentation item including any rst content including text, images, formulas, code-blocks, etc.

.. item:: SWRQT-MY_FIRST_REQUIREMENT Caption of my first requirement
    :value: 400
    :status: Approved
    :validated_by: ITEST-MY_FIRST_INTEGRATION_TEST
    :ext_polarion_reference: project_x:workitem_y
    :nocaptions:

    According to the Polarion reference, the software **shall** implement my first requirement.

Attributes can be added to the item, using the configured attribute keys (e.g. value in the above example). The content of the attribute is treated as a single string and should match the regular expression in configuration.

The relations to other documentation items can be specified as:

• a space-separated list of item ID’s, or

• items can be linked to on a newline (tabulated)

.. item:: SWRQT-MY_FIRST_REQUIREMENT Caption of my first requirement
    :validated_by:
        ITEST-MY_FIRST_INTEGRATION_TEST
        ITEST-MY_SECOND_INTEGRATION_TEST

The output will contain hyperlinks to all related items. By default, the caption for the target item is displayed for each of these related items. With the option nocaptions these captions can be omitted.

Adding relations outside of the item definitions

In some cases, it’s useful to add relations outside of the definition of the items involved. In that case, you can use the item-link directive as follows:

.. item-link::
    :sources: RQT1 RQT2
    :targets: TST3 TST4 TST5
    :type: validates

This directive has no representation in the documentation build output. It will just add an additional relationship to the items mentioned in sources and targets.

Adding description to attributes

Section traceability_config_attributes explain how attributes can be added to the configuration. It is possible to add content to the attributes. A detailed description can be added to an attribute definition:

• The name (id) of the attribute needs to match the configured attribute. This name is not case sensitive.

• Caption or short description of the attribute.

• Content of attribute including any rst content including text, images, formulas, code-blocks, etc.

.. item-attribute:: status The status of a requirement

    The status of the requirement explains whether it is *draft*, *under-review*, *approved* or *invalid*.

Manual link to documentation items

Manual links in RST documentation to any of the documentation items is possible using the :item: role:

For validating the :item:`SWRQT-MY_FIRST_REQUIREMENT`, we plan to use setup x in the y configuration.

Flat list of documentation items

A flat list of documentation items can be generated using a Python regular expression filter:

.. item-list:: All software requirements
    :filter: SWRQT
    :status: Appr
    :nocaptions:

where SWRQT (filter argument) can be replaced by any Python regular expression. Documentation items matching their ID to the given regular expression end up in the list.

where status can be replaced by any configured attribute, and Appr can be replaced by any Python regular expression. Documentation items where the status attribute matches the given regular expression end up in the list.

By default, the caption for every item in the list is shown. By providing the nocaptions flag, the caption can be omitted. This gives a smaller list, but also less details.

Matrix with attributes of documentation items

A matrix listing the attributes of documentation items can be generated using:

.. item-attributes-matrix:: Attributes for requirements
    :filter: SWRQT
    :status: Appr
    :attributes: status
    :sort: status
    :reverse:
    :transpose:
    :nocaptions:

where the filter argument can be replaced by any Python regular expression. Documentation items matching their ID to the given regular expression end up in the list.

where status can be replaced by any configured attribute, and Appr can be replaced by any Python regular expression. Documentation items where the status attribute matches the given regular expression end up in the list.

where attributes argument is a space-separated list of attributes that should be matched in the matrix.

Above arguments can be avoided, or left empty, in which case the table will contain all attributes for all documentation items.

Documentation items matching their ID to the given filter regular expression end up as rows in the generated table. The matching attribute values end up as columns in the generated table. Documentation items that don’t have a value for a certain attribute will have an empty cell at the corresponding location.

By default, the caption for every item in the table is shown. By providing the nocaptions flag, the caption can be omitted. This gives a smaller table, but also less details.

By default, items are sorted naturally based on their name. With the sort argument it is possible to sort on one or more attribute values alphabetically. When providing multiple attributes to sort on, the attribute keys are space-separated. With the reverse argument, the sorting is reversed.

By default, the attribute names are listed the header row and every item takes up a row. Depending on the number of items and attributes it could be better to transpose the generated matrix (swap columns for row) by providing the transpose flag.

Optionally, the class attribute can be specified to customize table output, especially useful when rendering to LaTeX. Normally the longtable class is used when the number of rows is greater than 30 which allows long tables to span multiple pages. By setting class to longtable manually, you can force the use of this environment.

Traceability matrix of documentation items

A traceability matrix of documentation items can be generated using:

.. item-matrix:: Requirements to test case description traceability
    :source: SWRQT
    :target: [IU]TEST
    :status: Appr
    :sourcetitle: Software requirements
    :targettitle: Integration and unit test cases
    :type: validated_by
    :nocaptions:
    :stats:

where the source and target arguments can be replaced by any Python regular expression.

where status can be replaced by any configured attribute, and Appr can be replaced by any Python regular expression. Only documentation items where the status attribute matches the given regular expression end up in the source part of the matrix. The attribute value is not used as a filter on the target part.

The type argument is a space-separated list of relationships that should be matched in the matrix. The sourcetitle and targettitle arguments are the titles of the columns in the generated matrix.

Documentation items matching their ID to the given source regular expression end up in the left column of the generated table. Documentation items matching their ID to the given target regular expression with a matching relationship (see type argument) will end up in the right column of the generated table.

By default, the caption for every item in the table is shown. By providing the nocaptions flag, the caption can be omitted. This gives a smaller table, but also less details.

By providing the stats flag, some statistics (coverage percentage) are calculated and displayed above the matrix. The plugin counts the number of items having a target item in the target-column (=covered or allocated), and the number of items having no target in the target-column (=not covered or allocated). And calculates a coverage/allocation percentage from these counts. If the stats flag is not given, this percentage is not displayed.

Optionally, the class attribute can be specified to customize table output, especially useful when rendering to LaTeX. Normally the longtable class is used when the number of rows is greater than 30 which allows long tables to span multiple pages. By setting class to longtable manually, you can force the use of this environment.

2D-matrix of documentation items

A 2D-matrix of documentation items can be generated using:

.. item-2d-matrix:: Requirements to test case description traceability
    :source: SWRQT
    :target: [IU]TEST
    :status: Appr
    :hit: x
    :miss:
    :type: validated_by

where the source and target arguments can be replaced by any Python regular expression.

where status can be replaced by any configured attribute, and Appr can be replaced by any Python regular expression. Only documentation items where the status attribute matches the given regular expression end up in the source part of the matrix. The attribute value is not used as a filter on the target part.

The type argument is a space-separated list of relationships that should be matched in the matrix.

Documentation items matching their ID to the given source regular expression end up as columns of the generated table. Documentation items matching their ID to the given target regular expression end up as rows of the generated table. Where source and target items have a matching relationship (see type argument) an ‘x’ will be placed in the cell at co-ordinates of source/target.

Captions for items in the 2D table are never shown, as it would give a too heavy loaded table.

Optionally, the class attribute can be specified to customize table output, especially useful when rendering to LaTeX. Normally the longtable class is used when the number of rows is greater than 30 which allows long tables to span multiple pages. By setting class to longtable manually, you can force the use of this environment.

Documentation items tree-view

Note: this feature is not supported when building for latex/pdf.

A tree-view of documentation items can be generated using:

.. item-tree:: Requirements tree view
    :top: SWRQT
    :top_relation_filter: depends_on
    :status: Appr
    :type: impacts_on validated_by
    :nocaptions:

where the top argument can be replaced by any Python regular expression. The top_relation_filter and type arguments are space-separated lists of relationships.

The directive generates an expandable tree of links to documentation items. A nested bullet list is generated with, at the top level, the top level documentation items. These are the ones matching their ID to the top regular expression and not having any relation of top_relation_filter kind to a documentation item matching the same top regular expression against its ID.

The status can be replaced by any configured attribute, and Appr can be replaced by any Python regular expression. Only documentation items where the status attribute matches the given regular expression end up in the tree.

Going deeper down this nested bullet list, the item’s relationships are checked: if there is a type relationship (type is a space-separated list of relationships), it gets added as a one-level-deeper item in the nested bullet list. This action is repeated recursively.

Warning

The type is a list of relationships, which cannot hold the forward and reverse relationship of a pair. This would give endless repetition of the same nesting and endless recursion in Python. The plugin checks the item-tree directives for this mistake!

By default, the caption for every item in the tree is shown. By providing the nocaptions flag, the caption can be omitted. This gives a smaller tree, but also less details.

Pie chart of documentation items

A pie chart of documentation items can be generated using:

.. item-piechart:: Test coverage of requirements with report results
    :id_set: RQT TEST TEST_REP
    :label_set: uncovered, covered, executed
    :result: error, fail, pass

where the id_set arguments can be replaced by any Python regular expression. The label_set and result arguments are comma-separated lists.

The id_set is a list of item IDs with at least two and at most three item IDs. The first item ID is the source, the second item ID is the target, and the optional third item ID is the target of the second. Adding a third item ID splits up the items with an existing relationship between the first and second ID.

The optional label_set holds the string labels for the pie chart. For source items without a relationship to a target item, the first label is used. For those with a relationship, but without a relationship between the second and third ID, the second label is used. The third label is used for items with both relationships covered. This attribute is optional. The labels in the example are the default values.

The optional result can be replaced by any configured attribute of the third item ID. Its arguments are possible values of this attribute, ordered in priority from high to low. Using this option splits up the slice with the third label. In this example an RQT item with multiple TEST items, one with a fail and others a pass as result value in the TEST_REP item, will be added to the fail slice of the pie chart.

Retrieving checklist values from GitLab/GitHub (advanced)

The plugin can add an additional attribute to a traceability item if its item ID exists in a checklist inside the description of a merge/pull request. Documentation items can be linked to a checklist by defining them with the checklist-item directive.

.. checklist-item:: PLAN-UNIT_TESTS Have you added unit tests for regression detection?

This directive gets treated the same as the item directive, except that an additional attribute gets added when the item’s ID exists in the checklist. The attribute’s value depends on the status of the checkbox. The plugin queries the API of GitLab/GitHub for the description of the configured merge request.

The configuration of this feature is stored in the configuration variable traceability_checklist.

traceability_checklist = {
    'private_token': config('PRIVATE_TOKEN'),
    'api_host_name': config('API_HOST_NAME'),
    'project_id': config('PROJECT_ID'),
    'merge_request_id': config('MERGE_REQUEST_ID'),
    'attribute_name': config('TARGET_ATTRIBUTE_NAME'),
    'attribute_to_str': config('TARGET_ATTRIBUTE_TO_STRING'),
    'attribute_values': config('TARGET_ATTRIBUTE_VALUES'),
}

In this default configuration the variables are fetched from the environment, e.g. by using a .env file.

# copy example .env to your .env
cp doc/.env.example .env

# add env variables by adjusting the template values in .env

• ATTRIBUTE_NAME is the identifier of the attribute to be added, e.g. checked.

• ATTRIBUTE_TO_STRING is the string representation (as to be rendered in html) of the attribute name, e.g. Answer.

• ATTRIBUTE_VALUES are two comma-separated attribute values, e.g. yes,no. The first value is used when the checkbox is checked and the second value when unchecked.

A query is sent to the GitLab/GitHub API to retrieve the status of every checkbox in the description of the merge/pull request. The traceability item’s ID is expected to follow the checkbox directly. Example of a valid checklist in Markdown:

- [x] PLAN-UNIT_TESTS Have you added unit tests for regression detection?
- [ ] PLAN-PACKAGE_TEST Have you tested the package?

GitLab

• PRIVATE_TOKEN is your personal access token that has API access.

• API_HOST_NAME is the host name of the API, e.g. https://gitlab.example.com/api/v4.

• PROJECT_ID is the ID of the project.

• MERGE_REQUEST_ID is the internal ID of the merge request.

GitHub

• PRIVATE_TOKEN is not needed for public repositories. Otherwise, it must be a personal access token with the access to the targeted scope.

• API_HOST_NAME is the host name of the GitHub REST API v3: https://api.github.com.

• PROJECT_ID defines the repository by specifying owner and repo separated by a forward slash, e.g. melexis/sphinx-traceability-extension.

• MERGE_REQUEST_ID is the pull request number.

Process

The Melexis.SWCC process has a Guideline for documenting in Restructured Text (RST). It holds guidelines for using the traceability plugin with naming conventions, templates, etc.