Fix false positives in cycle detection with child scopes. #398
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Currently, cycle detection works by assigning each constructor node an "order"/index for the scope it was given in. If an edge exists between an index and itself, a cycle is detected. When we create a subscope, we copy all of the parent's nodes to the child scope, but we do not copy their orders. This causes all root scope constructors to effectively have order 0 in the child scope (zero value for a mapping to int). This causes false positives when doing cycle detection as an edge from order 0 to order 0 gets detected. This PR fixes this bug by copying the order for constructor nodes from parent to child scope when a child scope is created. The added test case fails before this PR, passes with it. Ref: uber-go#397
Codecov Report
@@ Coverage Diff @@
## master #398 +/- ##
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Coverage 98.40% 98.40%
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Files 22 22
Lines 1502 1505 +3
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+ Hits 1478 1481 +3
Misses 15 15
Partials 9 9
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Currently, cycle detection works by assigning each constructor node an "order"/index for the scope it was given in. If a path exists between an index and itself, a cycle is detected.
When we create a subscope, we copy all of the parent's nodes to the child scope, but we do not copy their orders. This causes all root scope constructors to effectively have order 0 in the child scope (zero value for a mapping to int). This causes false positives when doing cycle detection as an edge from order 0 to order 0 gets detected.
This PR fixes this bug by copying the order for constructor nodes from parent to child scope when a child scope is created.
The added test case fails before this PR, passes with it.
Ref: #397