eSliderandCursor
c575341178
- Module github.com/eslider/go-config with env/yaml/json/ini packages - internal: source, keymap, merge, structconv, bytesutil - cmd/envc: convert, get, merge - docs/asr ASR-0001..0008, README/CHANGELOG/AGENTS refresh - golangci-lint v2 config; tests + fixtures Co-authored-by: Cursor <cursoragent@cursor.com>
27 lines
881 B
Markdown
27 lines
881 B
Markdown
# ASR-0005: Multi-source deep-merge semantics
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## Context
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Layered configuration (defaults file < local overrides < process environment) requires predictable composition rules.
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## Decision
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1. Sources are applied in **option order** (left → right). Each source parses to a `map[string]any`, then **`merge.DeepMerge`** folds them.
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2. **Maps recurse** — nested keys are unioned; existing nested maps are not replaced wholesale by a sibling scalar.
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3. **Scalar leaves** use **last-write-wins** (later source wins).
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4. **Slices** default to **`merge.Replace`**; **`WithSliceMerge(merge.Concat)`** appends prior and new slice elements.
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## Consequences
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- Env files and `WithCurrentEnvironment()` compose when ordered **lowest → highest** priority.
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- Tests lock behaviour via `fixtures/merge/*`.
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## Status
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Accepted — 2026-05-02.
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## References
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- ASR-0003
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- `internal/merge`
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