dependencies

Dependency naming

This package constructs the directed dependency graph for all components under the git.path. A component is identified by a coco.yaml file with the format:

# coco.yaml content

type: component
name: name of the component
dependencies:
  - list of
  - all other components
  - that this component
  - depends on directly

In the coco.yaml files dependencies are given from Downstream to Upstream, meaning that this file contains all dependencies that this component requires to work (a.k.a Upstream components). Therefore, the directed graph that can be constructed from the coco.yaml files flows from Downstream to Upstream components. For the identification which Downstream components are potentially affected by an Upstream change (and hence need to be tested in change validation), this flow direction is the inverse of what we need.

In this package the graph construction from a set of coco.yaml files and the inversion of the graph is done. For later consumption the inversed graph is represented from each node as map of maps. See the following examples

# service A depends on upstream services C and D

# graph from Downstream to Upstream

A -+ → C
   |
   + → D

# graph from Upstream to Downstream

C → A

D → A

# desired output

map[
  A: [],
  C: map[0:map[A:true]],
  D: map[0:map[A:true]],
]

# service A depends on upstream services C and D

# graph from Downstream to Upstream

A → + → C → E
    ↓   ↓
    + → D

# graph from Upstream to Downstream

A ← + ← C ← E
    ↑   ↑
    + ← D

# desired output

map[
  A: map[],
  C: map[0:map[A:true]],
  D: map[
    0:map[
      A:true,
      C:true,
    ]
  ],
  E: map[
    0:map[C:true],
    1:map[A:true],
  ]
]

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