Move PartialMatch field to Explanation struct and update related logic (

#2103)

- Previously, the `PartialMatch` field was returned for every hit, but
this caused confusion in complex queries involving disjunctions and
match queries. As a result, we moved `PartialMatch` to the score
explanation, where each subquery's explanation will include its own
`PartialMatch`. This field is set only if the query uses the
DisjunctionSearcher or scorer.

search/explanation.go

@@ -30,9 +30,10 @@ func init() {
 }
 
 type Explanation struct {
-	Value    float64        `json:"value"`
-	Message  string         `json:"message"`
-	Children []*Explanation `json:"children,omitempty"`
+	Value        float64        `json:"value"`
+	Message      string         `json:"message"`
+	PartialMatch bool           `json:"partial_match,omitempty"`
+	Children     []*Explanation `json:"children,omitempty"`
 }
 
 func (expl *Explanation) String() string {

search/scorer/scorer_disjunction.go

@@ -69,7 +69,7 @@ func (s *DisjunctionQueryScorer) Score(ctx *search.SearchContext, constituents [
 		ce := make([]*search.Explanation, 2)
 		ce[0] = rawExpl
 		ce[1] = &search.Explanation{Value: coord, Message: fmt.Sprintf("coord(%d/%d)", countMatch, countTotal)}
-		newExpl = &search.Explanation{Value: newScore, Message: "product of:", Children: ce}
+		newExpl = &search.Explanation{Value: newScore, Message: "product of:", Children: ce, PartialMatch: countMatch != countTotal}
 	}
 
 	// reuse constituents[0] as the return value

search/search.go

@@ -167,13 +167,6 @@ type DocumentMatch struct {
 	// results are completed
 	FieldTermLocations []FieldTermLocation `json:"-"`
 
-	// used to indicate if this match is a partial match
-	// in the case of a disjunction search
-	// this means that the match is partial because
-	// not all sub-queries matched
-	// if false, all the sub-queries matched
-	PartialMatch bool `json:"partial_match,omitempty"`
-
 	// used to indicate the sub-scores that combined to form the
 	// final score for this document match.  This is only populated
 	// when the search request's query is a DisjunctionQuery

search/searcher/search_disjunction_heap.go

@@ -218,9 +218,7 @@ func (s *DisjunctionHeapSearcher) Next(ctx *search.SearchContext) (
 				rv = s.scorer.ScoreAndExplBreakdown(ctx, s.matching, s.matchingIdxs, nil, s.numSearchers)
 			} else {
 				// score this match
-				partialMatch := len(s.matching) != len(s.searchers)
 				rv = s.scorer.Score(ctx, s.matching, len(s.matching), s.numSearchers)
-				rv.PartialMatch = partialMatch
 			}
 		}
 

search/searcher/search_disjunction_slice.go

@@ -230,9 +230,7 @@ func (s *DisjunctionSliceSearcher) Next(ctx *search.SearchContext) (
 				rv = s.scorer.ScoreAndExplBreakdown(ctx, s.matching, s.matchingIdxs, s.originalPos, s.numSearchers)
 			} else {
 				// score this match
-				partialMatch := len(s.matching) != len(s.searchers)
 				rv = s.scorer.Score(ctx, s.matching, len(s.matching), s.numSearchers)
-				rv.PartialMatch = partialMatch
 			}
 		}
 

search_test.go

@@ -1266,6 +1266,7 @@ func TestMatchQueryPartialMatch(t *testing.T) {
 	mq1.SetField("description")
 
 	sr := NewSearchRequest(mq1)
+	sr.Explain = true
 	res, err := idx.Search(sr)
 	if err != nil {
 		t.Fatal(err)
@@ -1274,11 +1275,17 @@ func TestMatchQueryPartialMatch(t *testing.T) {
 		t.Errorf("Expected 2 results, but got: %v", res.Total)
 	}
 	for _, hit := range res.Hits {
-		if hit.ID == "doc1" && hit.PartialMatch {
-			t.Errorf("Expected doc1 to be a full match")
-		}
-		if hit.ID == "doc2" && !hit.PartialMatch {
-			t.Errorf("Expected doc2 to be a partial match")
+		switch hit.ID {
+		case "doc1":
+			if hit.Expl.PartialMatch {
+				t.Errorf("Expected doc1 to be a full match")
+			}
+		case "doc2":
+			if !hit.Expl.PartialMatch {
+				t.Errorf("Expected doc2 to be a partial match")
+			}
+		default:
+			t.Errorf("Unexpected document ID: %s", hit.ID)
 		}
 	}
 
@@ -1288,6 +1295,7 @@ func TestMatchQueryPartialMatch(t *testing.T) {
 	mq2.SetFuzziness(2)
 
 	sr = NewSearchRequest(mq2)
+	sr.Explain = true
 	res, err = idx.Search(sr)
 	if err != nil {
 		t.Fatal(err)
@@ -1296,18 +1304,25 @@ func TestMatchQueryPartialMatch(t *testing.T) {
 		t.Errorf("Expected 2 results, but got: %v", res.Total)
 	}
 	for _, hit := range res.Hits {
-		if hit.ID == "doc1" && !hit.PartialMatch {
-			t.Errorf("Expected doc1 to be a partial match")
-		}
-		if hit.ID == "doc2" && hit.PartialMatch {
-			t.Errorf("Expected doc2 to be a full match")
+		switch hit.ID {
+		case "doc1":
+			if !hit.Expl.PartialMatch {
+				t.Errorf("Expected doc1 to be a partial match")
+			}
+		case "doc2":
+			if hit.Expl.PartialMatch {
+				t.Errorf("Expected doc2 to be a full match")
+			}
+		default:
+			t.Errorf("Unexpected document ID: %s", hit.ID)
 		}
 	}
 	// Test 3 - Two Docs hits, both full match
 	mq3 := NewMatchQuery("patrick")
 	mq3.SetField("description")
 
 	sr = NewSearchRequest(mq3)
+	sr.Explain = true
 	res, err = idx.Search(sr)
 	if err != nil {
 		t.Fatal(err)
@@ -1316,18 +1331,25 @@ func TestMatchQueryPartialMatch(t *testing.T) {
 		t.Errorf("Expected 2 results, but got: %v", res.Total)
 	}
 	for _, hit := range res.Hits {
-		if hit.ID == "doc1" && hit.PartialMatch {
-			t.Errorf("Expected doc1 to be a full match")
-		}
-		if hit.ID == "doc2" && hit.PartialMatch {
-			t.Errorf("Expected doc2 to be a full match")
+		switch hit.ID {
+		case "doc1":
+			if hit.Expl.PartialMatch {
+				t.Errorf("Expected doc1 to be a full match")
+			}
+		case "doc2":
+			if hit.Expl.PartialMatch {
+				t.Errorf("Expected doc2 to be a full match")
+			}
+		default:
+			t.Errorf("Unexpected document ID: %s", hit.ID)
 		}
 	}
 	// Test 4 - Two Docs hits, both partial match
 	mq4 := NewMatchQuery("patrick stewart manager")
 	mq4.SetField("description")
 
 	sr = NewSearchRequest(mq4)
+	sr.Explain = true
 	res, err = idx.Search(sr)
 	if err != nil {
 		t.Fatal(err)
@@ -1336,11 +1358,17 @@ func TestMatchQueryPartialMatch(t *testing.T) {
 		t.Errorf("Expected 2 results, but got: %v", res.Total)
 	}
 	for _, hit := range res.Hits {
-		if hit.ID == "doc1" && !hit.PartialMatch {
-			t.Errorf("Expected doc1 to be a partial match")
-		}
-		if hit.ID == "doc2" && !hit.PartialMatch {
-			t.Errorf("Expected doc2 to be a partial match")
+		switch hit.ID {
+		case "doc1":
+			if !hit.Expl.PartialMatch {
+				t.Errorf("Expected doc1 to be a full match")
+			}
+		case "doc2":
+			if !hit.Expl.PartialMatch {
+				t.Errorf("Expected doc2 to be a full match")
+			}
+		default:
+			t.Errorf("Unexpected document ID: %s", hit.ID)
 		}
 	}
 
@@ -1350,14 +1378,17 @@ func TestMatchQueryPartialMatch(t *testing.T) {
 	mq5.SetOperator(1)
 
 	sr = NewSearchRequest(mq5)
+	sr.Explain = true
 	res, err = idx.Search(sr)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if res.Total != 1 {
 		t.Errorf("Expected 1 result, but got: %v", res.Total)
 	}
-	if res.Hits[0].ID == "doc2" || res.Hits[0].PartialMatch {
+	hit := res.Hits[0]
+	fmt.Println(hit.Expl, hit.ID)
+	if hit.ID != "doc1" || hit.Expl.PartialMatch {
 		t.Errorf("Expected doc1 to be a full match")
 	}
 }