README
¶
Dot
The dot module generates a DOT file representation of a dependency graph.
Interpreting the graph
The graph should be read from left to right. The leftmost node in the graph (the root node) depends on its dependency tree to the right. An arrow from node_a to node_b in the graph means that node_b is consumed by node_a and that node_b is a parameter of node_a. The rendered graph holds the following kinds of nodes,
Nodes:
- Constructors [Rectangles]: Takes parameters and produces results.
- Results [Ovals]: Results inside a constructor are produced by that constructor. Results are consumed directly by other constructors and/or part of a group of results.
- Groups [Diamonds]: Represent value groups in fx. Multiple results can form a group. Any result linked to a group by an edge are members of that group. A group is a collection of results. Groups can also be parameters of constructors.
Edges:
- Solid Arrows: An arrow from node_a to node_b means that node_b is a parameter of node_a and that node_a depends on node_b.
- Dashed Arrows: A dashed arrow from node_a to node_b represents an optional dependency that node_a has on node_b.
Graph Colors:
- Red: Graph nodes are the root cause failures.
- Orange: Graph nodes are the transitive failures.
Testing and verifying changes
Unit tests and visualize golden tests are run with
$ make test
You can visualize the effect of your code changes by visualizing generated test graphs as pngs.
In the dig root directory, generate the graph DOT files with respect to your latest code changes.
$ go test -generate
Assuming that you have graphviz installed and are in the testdata directory, generate a png image representation of a graph for viewing.
$ dot -Tpng ${name_of_dot_file_in_testdata}.dot -o ${name_of_dot_file_in_testdata}.png
$ open ${name_of_dot_file_in_testdata}.png
Graph Pruning
If dot.Visualize is used to visualize an error graph, non-failing nodes are pruned out of the graph to make the error graph more readable to the user. Pruning increases readability since successful nodes clutter the graph and do not help the user debug errors.
Documentation
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Index ¶
Constants ¶
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Variables ¶
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Functions ¶
This section is empty.
Types ¶
type Ctor ¶
type Ctor struct {
Name string
Package string
File string
Line int
ID CtorID
Params []*Param
GroupParams []*Group
Results []*Result
ErrorType ErrorType
}
Ctor encodes a constructor provided to the container for the DOT graph.
type ErrorType ¶
type ErrorType int
ErrorType of a constructor or group is updated when they fail to build.
type FailedNodes ¶
type FailedNodes struct {
// RootCauses is a list of the point of failures. They are the root causes
// of failed invokes and can be either missing types (not provided) or
// error types (error providing).
RootCauses []*Result
// TransitiveFailures is the list of nodes that failed to build due to
// missing/failed dependencies.
TransitiveFailures []*Result
// contains filtered or unexported fields
}
FailedNodes is the nodes that failed in the graph.
type Graph ¶
type Graph struct {
Ctors []*Ctor
Groups []*Group
Failed *FailedNodes
// contains filtered or unexported fields
}
Graph is the DOT-format graph in a Container.
func (*Graph) AddMissingNodes ¶
AddMissingNodes adds missing nodes to the list of failed Results in the graph.
func (*Graph) FailGroupNodes ¶
FailGroupNodes finds and adds the failed grouped nodes to the list of failed Results in the graph, and updates the state of the group and constructor with the given id accordingly.
func (*Graph) FailNodes ¶
FailNodes adds results to the list of failed Results in the graph, and updates the state of the constructor with the given id accordingly.
func (*Graph) PruneSuccess ¶ added in v1.6.0
func (dg *Graph) PruneSuccess()
PruneSuccess removes elements from the graph that do not have failed results. Removing elements that do not have failing results makes the graph easier to debug, since non-failing nodes and edges can clutter the graph and don't help the user debug.
type Group ¶
type Group struct {
// Type is the type of values in the group.
Type reflect.Type
Name string
Results []*Result
ErrorType ErrorType
}
Group is a group node in the graph. Group represents an fx value group.
func NewGroup ¶
func NewGroup(k nodeKey) *Group
NewGroup creates a new group with information in the groupKey.
func (*Group) Attributes ¶
Attributes composes and returns a string of the Group node's attributes.
type Result ¶
type Result struct {
*Node
// GroupIndex is added to differentiate grouped values from one another.
// Since grouped values have the same type and group, their Node / string
// representations are the same so we need indices to uniquely identify
// the values.
GroupIndex int
}
Result is a result node in the graph. Results are the output of constructors.
func (*Result) Attributes ¶
Attributes composes and returns a string of the Result node's attributes.
Source Files