Fix remaining (?) edge case bugs, add tests

slice_test.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type testWriteCloser struct {
+	written int
+	closed  bool
+}
+
+func (twc *testWriteCloser) Close() error {
+	twc.closed = true
+	return nil
+}
+
+func (twc *testWriteCloser) Write(b []byte) (int, error) {
+	twc.written += len(b)
+	return len(b), nil
+}
+
+type testOutputter struct {
+	closers map[string]*testWriteCloser
+}
+
+func (to *testOutputter) CreatePathAndFile(fn string) (io.WriteCloser, error) {
+	to.closers[fn] = &testWriteCloser{}
+	return to.closers[fn], nil
+}
+
+func (to *testOutputter) Dump() string {
+	out := ""
+	for k, v := range to.closers {
+		out += fmt.Sprintf("%20s: %6d/%t\n", k, v.written, v.closed)
+	}
+	return out
+}
+
+func NewTestOutputter() *testOutputter {
+	to := testOutputter{}
+	to.closers = make(map[string]*testWriteCloser)
+	return &to
+}
+
+func TestXxx(t *testing.T) {
+
+	// testdata/gold.jpg: JPEG image data, JFIF standard 1.01, 794x447
+	f, err := os.Open("testdata/gold.jpg")
+	if err != nil {
+		panic(err)
+	}
+
+	// with a tile size larger than the image itself, we should
+	// get a single image at zoom level 0
+	testOutputter := NewTestOutputter()
+	processImage(f, "indy", defaultPathTemplate, "jpg", 1000, 1, testOutputter)
+	t.Log(testOutputter.Dump())
+	assert.Equal(t, 1, len(testOutputter.closers))
+	assert.Equal(t, 28082, testOutputter.closers["indy-0-0-0.jpg"].written)
+
+	f, _ = os.Open("testdata/gold.jpg")
+
+	// with a tilesize smaller than *one* of the dimensions, 3 tiles
+	// 1@zoom 0, 2@zoom 1
+	testOutputter = NewTestOutputter()
+	processImage(f, "indy", defaultPathTemplate, "jpg", 500, 1, testOutputter)
+	t.Log(testOutputter.Dump())
+	assert.Equal(t, 3, len(testOutputter.closers))
+	assert.Equal(t, 10304, testOutputter.closers["indy-0-0-0.jpg"].written)
+	assert.Equal(t, 18014, testOutputter.closers["indy-1-0-0.jpg"].written)
+	assert.Equal(t, 10749, testOutputter.closers["indy-1-1-0.jpg"].written)
+
+	f, _ = os.Open("testdata/gold.jpg")
+
+	// with a tilesize smaller than *both* of the dimensions, 5 tiles
+	// zoom 0, zoom 1 x 4
+	testOutputter = NewTestOutputter()
+	processImage(f, "indy", defaultPathTemplate, "jpg", 400, 1, testOutputter)
+	t.Log(testOutputter.Dump())
+	assert.Equal(t, 5, len(testOutputter.closers))
+	assert.Equal(t, 10304, testOutputter.closers["indy-0-0-0.jpg"].written)
+	assert.Equal(t, 12607, testOutputter.closers["indy-1-0-0.jpg"].written)
+	assert.Equal(t, 12050, testOutputter.closers["indy-1-1-0.jpg"].written)
+	assert.Equal(t, 2722, testOutputter.closers["indy-1-0-1.jpg"].written)
+	assert.Equal(t, 2477, testOutputter.closers["indy-1-1-1.jpg"].written)
+
+}