From 4eafafcf709c16f9a72bdc0b427a2d56c34291b8 Mon Sep 17 00:00:00 2001
From: Luca Ongaro <mail@lucaongaro.eu>
Date: Mon, 15 May 2023 22:55:57 +0200
Subject: [PATCH] Pass stored fields to boostDocument callback

This makes it more convenient to perform dynamic boosting.
---
 CHANGELOG.md           |  5 +++++
 src/MiniSearch.test.js |  9 +++++----
 src/MiniSearch.ts      | 11 +++++++----
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e347e08d..9a3db9de 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 `MiniSearch` follows [semantic versioning](https://semver.org/spec/v2.0.0.html).
 
+# unreleased
+
+  - Pass stored fields to the `boostDocument` callback function, making it
+    easier to perform dynamic document boosting.
+
 # v6.0.1
 
   - [fix] The `boost` search option now does not interfere with the `fields`
diff --git a/src/MiniSearch.test.js b/src/MiniSearch.test.js
index 7f5acabd..31e17035 100644
--- a/src/MiniSearch.test.js
+++ b/src/MiniSearch.test.js
@@ -1109,14 +1109,15 @@ describe('MiniSearch', () => {
       expect(results.map(({ id }) => id)).toEqual([2, 1])
     })
 
-    it('boosts documents by calling boostDocument with document ID and term', () => {
-      const query = 'divina commedia'
+    it('boosts documents by calling boostDocument with document ID, term, and stored fields', () => {
+      const query = 'divina commedia nova'
       const boostFactor = 1.234
       const boostDocument = jest.fn((id, term) => boostFactor)
       const resultsWithoutBoost = ms.search(query)
       const results = ms.search(query, { boostDocument })
-      expect(boostDocument).toHaveBeenCalledWith(1, 'divina')
-      expect(boostDocument).toHaveBeenCalledWith(1, 'commedia')
+      expect(boostDocument).toHaveBeenCalledWith(1, 'divina', {})
+      expect(boostDocument).toHaveBeenCalledWith(1, 'commedia', {})
+      expect(boostDocument).toHaveBeenCalledWith(3, 'nova', { category: 'poetry' })
       expect(results[0].score).toBeCloseTo(resultsWithoutBoost[0].score * boostFactor)
     })
 
diff --git a/src/MiniSearch.ts b/src/MiniSearch.ts
index 0af6c7c5..77b1cdee 100644
--- a/src/MiniSearch.ts
+++ b/src/MiniSearch.ts
@@ -38,9 +38,12 @@ export type SearchOptions = {
   /**
    * Function to calculate a boost factor for documents. It takes as arguments
    * the document ID, and a term that matches the search in that document, and
-   * should return a boosting factor.
+   * the value of the stored fields for the document (if any).  It should return
+   * a boosting factor: a number higher than 1 increases the computed score, a
+   * number lower than 1 decreases the score, and a falsy value skips the search
+   * result completely.
    */
-  boostDocument?: (documentId: any, term: string) => number,
+  boostDocument?: (documentId: any, term: string, storedFields?: Record<string, unknown>) => number,
 
   /**
    * Controls whether to perform prefix search. It can be a simple boolean, or a
@@ -1572,7 +1575,7 @@ export default class MiniSearch<T = any> {
     termWeight: number,
     fieldTermData: FieldTermData | undefined,
     fieldBoosts: { [field: string]: number },
-    boostDocumentFn: ((id: any, term: string) => number) | undefined,
+    boostDocumentFn: ((id: any, term: string, storedFields?: Record<string, unknown>) => number) | undefined,
     bm25params: BM25Params,
     results: RawResult = new Map()
   ): RawResult {
@@ -1595,7 +1598,7 @@ export default class MiniSearch<T = any> {
           continue
         }
 
-        const docBoost = boostDocumentFn ? boostDocumentFn(this._documentIds.get(docId), derivedTerm) : 1
+        const docBoost = boostDocumentFn ? boostDocumentFn(this._documentIds.get(docId), derivedTerm, this._storedFields.get(docId)) : 1
         if (!docBoost) continue
 
         const termFreq = fieldTermFreqs.get(docId)!