fix: BodyContainsBytes & BodyContainsString used with And/Or

Both "rearm" the body before (re-)reading it, so they can be used
several times in a same matcher (combined with Or & And).

At the same time, simplify the body copy and make the "rearming" more
performant.

Closes #145.

Signed-off-by: Maxime Soulé <btik-git@scoubidou.com>

export_test.go

@@ -38,10 +38,6 @@ func (b *bodyCopyOnRead) Body() io.ReadCloser {
 	return b.body
 }
 
-func (b *bodyCopyOnRead) Buf() []byte {
-	return b.buf
-}
-
 func (b *bodyCopyOnRead) Rearm() {
 	b.rearm()
 }

match.go

@@ -106,6 +106,7 @@ type MatcherFunc func(req *http.Request) bool
 func matcherFuncOr(mfs []MatcherFunc) MatcherFunc {
 	return func(req *http.Request) bool {
 		for _, mf := range mfs {
+			rearmBody(req)
 			if mf(req) {
 				return true
 			}
@@ -120,6 +121,7 @@ func matcherFuncAnd(mfs []MatcherFunc) MatcherFunc {
 	}
 	return func(req *http.Request) bool {
 		for _, mf := range mfs {
+			rearmBody(req)
 			if !mf(req) {
 				return false
 			}
@@ -224,6 +226,7 @@ func NewMatcher(name string, fn MatcherFunc) Matcher {
 func BodyContainsBytes(subslice []byte) Matcher {
 	return NewMatcher("",
 		func(req *http.Request) bool {
+			rearmBody(req)
 			b, err := ioutil.ReadAll(req.Body)
 			return err == nil && bytes.Contains(b, subslice)
 		})
@@ -243,6 +246,7 @@ func BodyContainsBytes(subslice []byte) Matcher {
 func BodyContainsString(substr string) Matcher {
 	return NewMatcher("",
 		func(req *http.Request) bool {
+			rearmBody(req)
 			b, err := ioutil.ReadAll(req.Body)
 			return err == nil && bytes.Contains(b, []byte(substr))
 		})
@@ -465,27 +469,40 @@ func (m matchRouteKey) String() string {
 	return m.RouteKey.String() + " <" + m.name + ">"
 }
 
-// bodyCopyOnRead copies body content to buf on first Read(), except
+func rearmBody(req *http.Request) {
+	if req != nil {
+		if body, ok := req.Body.(interface{ rearm() }); ok {
+			body.rearm()
+		}
+	}
+}
+
+type buffer struct {
+	*bytes.Reader
+}
+
+func (b buffer) Close() error {
+	return nil
+}
+
+// bodyCopyOnRead mutates body into a buffer on first Read(), except
 // if body is nil or http.NoBody. In this case, EOF is returned for
-// each Read() and buf stays to nil.
+// each Read() and body stays untouched.
 type bodyCopyOnRead struct {
 	body io.ReadCloser
-	buf  []byte
 }
 
 func (b *bodyCopyOnRead) rearm() {
-	if b.buf != nil {
-		b.body = ioutil.NopCloser(bytes.NewReader(b.buf))
+	if buf, ok := b.body.(buffer); ok {
+		buf.Seek(0, io.SeekStart) //nolint:errcheck
 	} // else b.body contains the original body, so don't touch
 }
 
 func (b *bodyCopyOnRead) copy() {
-	if b.buf == nil && b.body != nil && b.body != http.NoBody {
-		var body bytes.Buffer
-		io.Copy(&body, b.body) //nolint: errcheck
+	if _, ok := b.body.(buffer); !ok && b.body != nil && b.body != http.NoBody {
+		buf, _ := ioutil.ReadAll(b.body)
 		b.body.Close()
-		b.buf = body.Bytes()
-		b.body = ioutil.NopCloser(bytes.NewReader(b.buf))
+		b.body = buffer{bytes.NewReader(buf)}
 	}
 }
 
@@ -500,9 +517,3 @@ func (b *bodyCopyOnRead) Read(p []byte) (n int, err error) {
 func (b *bodyCopyOnRead) Close() error {
 	return nil
 }
-
-// Len returns the buffer total length, whatever the Read position in body is.
-func (b *bodyCopyOnRead) Len() int {
-	b.copy()
-	return len(b.buf)
-}

match_test.go

@@ -84,18 +84,30 @@ func TestNewMatcher(t *testing.T) {
 		return req
 	}
 
+	reqCopyBody := func(t testing.TB, body string, header ...string) *http.Request {
+		req := req(t, body, header...)
+		req.Body = httpmock.NewBodyCopyOnRead(req.Body)
+		return req
+	}
+
 	t.Run("BodyContainsBytes", func(t *testing.T) {
 		m := httpmock.BodyContainsBytes([]byte("ip"))
 		td.Cmp(t, m.Name(), autogenName)
 		td.CmpTrue(t, m.Check(req(t, "pipo")))
 		td.CmpFalse(t, m.Check(req(t, "bingo")))
+
+		td.CmpTrue(t, m.Check(reqCopyBody(t, "pipo")))
+		td.CmpFalse(t, m.Check(reqCopyBody(t, "bingo")))
 	})
 
 	t.Run("BodyContainsString", func(t *testing.T) {
 		m := httpmock.BodyContainsString("ip")
 		td.Cmp(t, m.Name(), autogenName)
 		td.CmpTrue(t, m.Check(req(t, "pipo")))
 		td.CmpFalse(t, m.Check(req(t, "bingo")))
+
+		td.CmpTrue(t, m.Check(reqCopyBody(t, "pipo")))
+		td.CmpFalse(t, m.Check(reqCopyBody(t, "bingo")))
 	})
 
 	t.Run("HeaderExists", func(t *testing.T) {
@@ -394,15 +406,17 @@ func TestBodyCopyOnRead(t *testing.T) {
 		bc := httpmock.NewBodyCopyOnRead(body)
 
 		bc.Rearm()
-		td.CmpNil(t, bc.Buf())
+		td.Cmp(t, body, bc.Body(), "rearm didn't touch anything")
 
 		var buf [4]byte
 		n, err := bc.Read(buf[:])
 		td.CmpNoError(t, err)
 		td.Cmp(t, n, 4)
 		td.CmpString(t, buf[:], "BODY")
 
-		td.CmpString(t, bc.Buf(), "BODY", "Original body has been copied internally")
+		td.Cmp(t, body, td.Not(bc.Body()), "Original body has been copied internally")
+
+		td.CmpNoError(t, bc.Body().Close()) // for coverage... :)
 
 		n, err = bc.Read(buf[:])
 		td.Cmp(t, err, io.EOF)
@@ -435,55 +449,24 @@ func TestBodyCopyOnRead(t *testing.T) {
 			bc := httpmock.NewBodyCopyOnRead(tc.body)
 
 			bc.Rearm()
-			td.CmpNil(t, bc.Buf())
+			td.Cmp(t, tc.body, bc.Body(), "rearm didn't touch anything")
 
 			var buf [4]byte
 			n, err := bc.Read(buf[:])
 			td.Cmp(t, err, io.EOF)
 			td.Cmp(t, n, 0)
-			td.CmpNil(t, bc.Buf())
-			td.Cmp(t, bc.Body(), tc.body)
+			td.Cmp(t, bc.Body(), tc.body, "body is not altered")
 
 			bc.Rearm()
 
 			n, err = bc.Read(buf[:])
 			td.Cmp(t, err, io.EOF)
 			td.Cmp(t, n, 0)
-			td.CmpNil(t, bc.Buf())
-			td.Cmp(t, bc.Body(), tc.body)
+			td.Cmp(t, bc.Body(), tc.body, "body is not altered")
 
 			td.CmpNoError(t, bc.Close())
 		})
 	}
-
-	t.Run("len", func(t *testing.T) {
-		testCases := []struct {
-			name     string
-			bc       interface{ Len() int }
-			expected int
-		}{
-			{
-				name:     "nil",
-				bc:       httpmock.NewBodyCopyOnRead(nil),
-				expected: 0,
-			},
-			{
-				name:     "no body",
-				bc:       httpmock.NewBodyCopyOnRead(http.NoBody),
-				expected: 0,
-			},
-			{
-				name:     "filled",
-				bc:       httpmock.NewBodyCopyOnRead(ioutil.NopCloser(bytes.NewReader([]byte(`BODY`)))),
-				expected: 4,
-			},
-		}
-		for _, tc := range testCases {
-			t.Run(tc.name, func(t *testing.T) {
-				td.Cmp(t, tc.bc.Len(), tc.expected)
-			})
-		}
-	})
 }
 
 func TestExtractPackage(t *testing.T) {

transport_test.go

@@ -123,6 +123,12 @@ func TestRegisterMatcherResponder(t *testing.T) {
 			}),
 		NewStringResponder(200, "body-FOO"))
 
+	RegisterMatcherResponder("POST", "/foo",
+		BodyContainsString("xxx").
+			Or(BodyContainsString("yyy")).
+			WithName("03-body-xxx|yyy"),
+		NewStringResponder(200, "body-xxx|yyy"))
+
 	RegisterResponder("POST", "/foo", NewStringResponder(200, "default"))
 
 	RegisterNoResponder(NewNotFoundResponder(nil))
@@ -156,6 +162,16 @@ func TestRegisterMatcherResponder(t *testing.T) {
 			body:         "FOO",
 			expectedBody: "body-FOO",
 		},
+		{
+			name:         "body xxx",
+			body:         "...xxx...",
+			expectedBody: "body-xxx|yyy",
+		},
+		{
+			name:         "body yyy",
+			body:         "...yyy...",
+			expectedBody: "body-xxx|yyy",
+		},
 		{
 			name:         "default",
 			body:         "ANYTHING",
@@ -194,12 +210,13 @@ func TestRegisterMatcherResponder(t *testing.T) {
 			"text/plain",
 			strings.NewReader("ANYTHING"),
 		)
-		assert.HasSuffix(err, `Responder not found for POST http://test.com/foo despite 3 matchers: ["00-header-foo=bar" "01-body-BAR" "02-body-FOO"]`)
+		assert.HasSuffix(err, `Responder not found for POST http://test.com/foo despite 4 matchers: ["00-header-foo=bar" "01-body-BAR" "02-body-FOO" "03-body-xxx|yyy"]`)
 	})
 
-	// Remove 2 matcher responders
+	// Remove 3 matcher responders
 	RegisterMatcherResponder("POST", "/foo", NewMatcher("01-body-BAR", nil), nil)
 	RegisterMatcherResponder("POST", "/foo", NewMatcher("02-body-FOO", nil), nil)
+	RegisterMatcherResponder("POST", "/foo", NewMatcher("03-body-xxx|yyy", nil), nil)
 
 	assert.Run("not found despite 1", func(assert *td.T) {
 		_, err := http.Post(