Add YAML anchor and alias support for GitHub Actions workflows #557
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Implements two-pass YAML parsing to resolve anchors (&anchor) and aliases (*alias) before linting, matching GitHub Actions' native YAML support. - Add containsAnchorsOrAliases() to detect anchor usage - Add resolveYAMLAnchors() using unmarshal/marshal strategy - Modify Parse() to resolve anchors when present - Add comprehensive test suite covering various anchor scenarios - Preserve backward compatibility for workflows without anchors - Maintain error detection and line number reporting after resolution Fixes workflows that previously failed with "alias node but mapping node is expected" errors when using YAML anchors supported by GitHub Actions.
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Please note that both lint and test FAIL but they also FAIL on |
| // containsAnchorsOrAliases recursively checks if a YAML node tree contains any anchors or aliases | ||
| func containsAnchorsOrAliases(node *yaml.Node) bool { | ||
| if node.Anchor != "" || node.Alias != nil { | ||
| return true |
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I had added anchor support in nektos/act yaml validator a while back at nektos/act#5893
e.g. https://github.com/nektos/act/blob/5e62222f80b8847de5dfced0527eaaeca3303168/pkg/schema/schema.go#L241C1-L243C3 I then traverse over alias and just handle it as if there were no alias.
Some suggestions from my side, using yaml.Node also heavily.
Just do *node = node.Alias and skip a lot of serializing / deserializing?
Otherwise assign node.Alias where you read this node pointer.
if node.Anchor != ""
just do node.Anchor = "" or remove the assert that require this to be cleared if any.
If I didn't produce a big bug in act, then this improves the code in my opinion
Otherwise use yaml.Node.Encode() and yaml.Node.Decode to replace marshall and unmarshall, this would avoid generating a text representation of the yaml that is not needed.
Serializing the yaml.Node into an interface may break diagnostic features of actionlint regardless if you use yaml.Node or text as medium for reading the yaml again.
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Thank you so much for the help, those are good tips!
Implements two-pass YAML parsing to resolve anchors (&anchor) and aliases (*alias) before linting, matching GitHub Actions' native YAML support.
Fixes workflows that previously failed with "alias node but mapping node is expected" errors when using YAML anchors supported by GitHub Actions.
Fixes #133
The support for this just landed: actions/runner#1182