Backfill tests for TF-IDF and norm calculations

lib/document_test.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestNormalizeTfIdf(t *testing.T) {
+	tm := TermMap{
+		"foo": 2.0,
+		"bar": 3.0,
+		"baz": 4.0,
+	}
+
+	tests := []struct {
+		doc    Document
+		idf    TermMap
+		expDoc Document
+	}{
+		{
+			Document{
+				TermFreq: TermMap{},
+			},
+			tm,
+			Document{
+				TfIdf: TermMap{},
+				Norm:  0.0,
+			},
+		},
+		{
+			Document{
+				TermFreq: TermMap{
+					"foo": 3.0,
+					"bar": 4.0,
+					"baz": 5.0,
+				},
+			},
+			tm,
+			Document{
+				TfIdf: TermMap{
+					"foo": 6.0,
+					"bar": 12.0,
+					"baz": 20.0,
+				},
+				Norm: 24.0832,
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		tc.doc.NormalizeTfIdf(tc.idf)
+
+		if !reflect.DeepEqual(tc.doc.TfIdf, tc.expDoc.TfIdf) {
+			t.Errorf("got %v, wanted %v", tc.doc.TfIdf, tc.expDoc.TfIdf)
+		}
+
+		if !approxEq(tc.doc.Norm, tc.expDoc.Norm) {
+			t.Errorf("got %.4f, wanted %.4f", tc.doc.Norm, tc.expDoc.Norm)
+		}
+
+		if tc.doc.TermFreq != nil {
+			t.Errorf("got %v, wanted nil", tc.doc.TermFreq)
+		}
+	}
+}
+func TestCalcNorm(t *testing.T) {
+	tests := []struct {
+		doc      Document
+		expected float64
+	}{
+		{
+			Document{
+				TfIdf: TermMap{},
+			},
+			0.0,
+		},
+		{
+			Document{
+				TfIdf: TermMap{
+					"foo": 2.0,
+					"bar": 3.0,
+					"baz": 4.0,
+				},
+			},
+			5.3852,
+		},
+	}
+
+	for _, tc := range tests {
+		got := tc.doc.calcNorm()
+
+		if !approxEq(got, tc.expected) {
+			t.Errorf("got %.4f, wanted %.4f", got, tc.expected)
+		}
+	}
+}