fix: deepMerge no longer mutates its arguments - #350
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richard-willis-chevin wants to merge 3 commits into
Open
fix: deepMerge no longer mutates its arguments#350richard-willis-chevin wants to merge 3 commits into
richard-willis-chevin wants to merge 3 commits into
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deepMerge merged into its target and returned it, and also assigned into its source. Generated hooks call deepMerge(fetcherOptions, variables), and fetcherOptions comes from a single useContext() call per hook instance, so that object is shared by every call of the hook. Each call therefore leaked its payload into the next: concurrent writes could all send the last one's body, sequential writes carried stale fields from the previous one, and the caller's own variables object was rewritten behind its back. Every request stayed well formed and succeeded, so the corruption was silent. deepMerge now builds a new object and mutates neither argument. It also only recurses when both sides are plain objects, so arrays are replaced rather than merged by index, and FormData/File bodies are passed through untouched. The existing merge test is unchanged and still passes, so the behaviour fabien0102#284 introduced is preserved. Closes fabien0102#349
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Fixes #349.
It now builds a new object and mutates neither argument, and only recurses when both sides are plain objects — so arrays are replaced rather than merged by index, and
FormData/Filebodies pass through untouched.The existing "should merge two objects" test is unchanged and still passes, so the behaviour #284 added is preserved. The four new tests all fail against the previous implementation.
Also updated the committed example output and one inline snapshot, both of which embed the generated helper.