Feature/1838 actor creation destruction

[Valentine14th]

📑 Summary

Allow for the creation and destruction of actors during a sequence by messages. To do so, add a creating or destroying directive before the message, as follows:

create participant B
A --> B: Hello

Create directives support actor/participant distinction and aliases. The sender or the recipient of a message can be destroyed but only the recipient can be created. The result is as follows for:

sequenceDiagram
    Alice->>Bob: Hello Bob, how are you ?
    Bob->>Alice: Fine, thank you. And you?
    create participant Carl
    Alice->>Carl: Hi Carl!
    create actor D as Donald
    Carl->>D: Hi!
    destroy Carl
    Alice-xCarl: We are too many
    destroy Bob
    Bob->>Alice: I agree

Resolves #1838

📏 Design Decisions

The jison parser was updated to process create and destroy directives. The sequenceDb.js database was updated to contain 2 new maps: createdActors and destroyedActors, which map an actor id to its creating/destroying message id. These are used in sequenceRenderer.js, where, in the draw() function, the message processing loop was updated to adjust actor rendering data based on the 2 maps, using the new adjustCreatedDestroyedData() function.

📋 Tasks

Make sure you

• 📖 have read the contribution guidelines
• 💻 have added unit/e2e tests (if appropriate)
• 📓 have added documentation (if appropriate)
• 🔖 targeted develop branch

[sidharthv96]

This is excellent work @Valentine14th !
Good code, conventions, tests, everything. 🚀

[codecov]

Codecov Report

Merging #4466 (dfc4665) into develop (29c866b) will decrease coverage by 17.30%.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff              @@
##           develop    #4466       +/-   ##
============================================
- Coverage    77.41%   60.11%   -17.30%     
============================================
  Files          139       53       -86     
  Lines        16587     9109     -7478     
  Branches       509       21      -488     
============================================
- Hits         12841     5476     -7365     
+ Misses        3638     3633        -5     
+ Partials       108        0      -108     

Flag	Coverage Δ
e2e	?
unit	60.11% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

see 133 files with indirect coverage changes

[mermaid-bot]

@Valentine14th, Thank you for the contribution!
You are now eligible for a year of Premium account on MermaidChart.
Sign up with your GitHub account to activate.

[habovh]

@Valentine14th @sidharthv96 I'd like to report an issue with this feature. It's not possible to set the order of participants that are later created.

Using the provided example, let's try to move Carl as the first participant, then Bob and Alice. This does not work with the following error:

Error: It is not possible to have actors with the same id, even if one is destroyed before the next is created. Use 'AS' aliases to simulate the behavior

sequenceDiagram
    %% the next line is breaking the diagram
    participant Carl
    participant Bob
    participant Alice
    Alice->>Bob: Hello Bob, how are you ?
    Bob->>Alice: Fine, thank you. And you?
    create participant Carl
    Alice->>Carl: Hi Carl!
    create actor D as Donald
    Carl->>D: Hi!
    destroy Carl
    Alice-xCarl: We are too many
    destroy Bob
    Bob->>Alice: I agree

Loading

Is there a way around this issue to have better control on the ordering of actors/participants?

[MarchandMD]

Experienced similar issue; for me it was the create participant that caused the error.

create participant typically creates a vertically indented participant, which is the expectation

sequenceDiagram
    create participant master
    create participant feature
    master->>feature: branch
    activate feature

Loading

---
title: removed the create keyword
---
sequenceDiagram
    participant master
    participant feature
    master->>feature: branch
    activate feature

Loading