added test for query norm

search/scorer_term_test.go

@@ -154,3 +154,88 @@ func TestTermScorer(t *testing.T) {
 	}
 
 }
+
+func TestTermScorerWithQueryNorm(t *testing.T) {
+
+	query := TermQuery{
+		Term:     "beer",
+		Field:    "desc",
+		BoostVal: 3.0,
+		Explain:  true,
+	}
+
+	var docTotal uint64 = 100
+	var docTerm uint64 = 9
+	scorer := NewTermQueryScorer(&query, docTotal, docTerm, true)
+	idf := 1.0 + math.Log(float64(docTotal)/float64(docTerm+1.0))
+
+	scorer.SetQueryNorm(2.0)
+
+	tests := []struct {
+		termMatch *index.TermFieldDoc
+		result    *DocumentMatch
+	}{
+		{
+			termMatch: &index.TermFieldDoc{
+				ID:   "one",
+				Freq: 1,
+				Norm: 1.0,
+			},
+			result: &DocumentMatch{
+				ID:    "one",
+				Score: math.Sqrt(1.0) * idf * 3.0 * idf * 2.0,
+				Expl: &Explanation{
+					Value:   math.Sqrt(1.0) * idf * 3.0 * idf * 2.0,
+					Message: "weight(desc:beer^3.000000 in one), product of:",
+					Children: []*Explanation{
+						&Explanation{
+							Value:   2.0 * idf * 3.0,
+							Message: "queryWeight(desc:beer^3.000000), product of:",
+							Children: []*Explanation{
+								&Explanation{
+									Value:   3,
+									Message: "boost",
+								},
+								&Explanation{
+									Value:   idf,
+									Message: "idf(docFreq=9, maxDocs=100)",
+								},
+								&Explanation{
+									Value:   2,
+									Message: "queryNorm",
+								},
+							},
+						},
+						&Explanation{
+							Value:   math.Sqrt(1.0) * idf,
+							Message: "fieldWeight(desc:beer in one), product of:",
+							Children: []*Explanation{
+								&Explanation{
+									Value:   1,
+									Message: "tf(termFreq(desc:beer)=1",
+								},
+								&Explanation{
+									Value:   1,
+									Message: "fieldNorm(field=desc, doc=one)",
+								},
+								&Explanation{
+									Value:   idf,
+									Message: "idf(docFreq=9, maxDocs=100)",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		actual := scorer.Score(test.termMatch)
+
+		if !reflect.DeepEqual(actual, test.result) {
+			t.Errorf("expected %#v got %#v for %#v", test.result, actual, test.termMatch)
+		}
+	}
+
+}