Fixed #34657 -- Made assert(Not)Contains/assertInHTML display haystacks in error messages.

2 files changed, 112 insertions, 18 deletions

diff --git a/tests/test_client_regress/tests.py b/tests/test_client_regress/tests.py
index 726d1dcf8f..d5b9807f4d 100644
--- a/tests/test_client_regress/tests.py
+++ b/tests/test_client_regress/tests.py
@@ -80,86 +80,141 @@ class AssertContainsTests(SimpleTestCase):
         try:
             self.assertNotContains(response, "once")
         except AssertionError as e:
-            self.assertIn("Response should not contain 'once'", str(e))
+            self.assertIn(
+                "'once' unexpectedly found in the following response\n"
+                f"{response.content}",
+                str(e),
+            )
         try:
             self.assertNotContains(response, "once", msg_prefix="abc")
         except AssertionError as e:
-            self.assertIn("abc: Response should not contain 'once'", str(e))
+            self.assertIn(
+                "abc: 'once' unexpectedly found in the following response\n"
+                f"{response.content}",
+                str(e),
+            )
 
         try:
             self.assertContains(response, "never", 1)
         except AssertionError as e:
             self.assertIn(
-                "Found 0 instances of 'never' in response (expected 1)", str(e)
+                "Found 0 instances of 'never' (expected 1) in the following response\n"
+                f"{response.content}",
+                str(e),
             )
         try:
             self.assertContains(response, "never", 1, msg_prefix="abc")
         except AssertionError as e:
             self.assertIn(
-                "abc: Found 0 instances of 'never' in response (expected 1)", str(e)
+                "abc: Found 0 instances of 'never' (expected 1) in the following "
+                f"response\n{response.content}",
+                str(e),
             )
 
         try:
             self.assertContains(response, "once", 0)
         except AssertionError as e:
             self.assertIn(
-                "Found 1 instances of 'once' in response (expected 0)", str(e)
+                "Found 1 instances of 'once' (expected 0) in the following response\n"
+                f"{response.content}",
+                str(e),
             )
         try:
             self.assertContains(response, "once", 0, msg_prefix="abc")
         except AssertionError as e:
             self.assertIn(
-                "abc: Found 1 instances of 'once' in response (expected 0)", str(e)
+                "abc: Found 1 instances of 'once' (expected 0) in the following "
+                f"response\n{response.content}",
+                str(e),
             )
 
         try:
             self.assertContains(response, "once", 2)
         except AssertionError as e:
             self.assertIn(
-                "Found 1 instances of 'once' in response (expected 2)", str(e)
+                "Found 1 instances of 'once' (expected 2) in the following response\n"
+                f"{response.content}",
+                str(e),
             )
         try:
             self.assertContains(response, "once", 2, msg_prefix="abc")
         except AssertionError as e:
             self.assertIn(
-                "abc: Found 1 instances of 'once' in response (expected 2)", str(e)
+                "abc: Found 1 instances of 'once' (expected 2) in the following "
+                f"response\n{response.content}",
+                str(e),
             )
 
         try:
             self.assertContains(response, "twice", 1)
         except AssertionError as e:
             self.assertIn(
-                "Found 2 instances of 'twice' in response (expected 1)", str(e)
+                "Found 2 instances of 'twice' (expected 1) in the following response\n"
+                f"{response.content}",
+                str(e),
             )
         try:
             self.assertContains(response, "twice", 1, msg_prefix="abc")
         except AssertionError as e:
             self.assertIn(
-                "abc: Found 2 instances of 'twice' in response (expected 1)", str(e)
+                "abc: Found 2 instances of 'twice' (expected 1) in the following "
+                f"response\n{response.content}",
+                str(e),
             )
 
         try:
             self.assertContains(response, "thrice")
         except AssertionError as e:
-            self.assertIn("Couldn't find 'thrice' in response", str(e))
+            self.assertIn(
+                f"Couldn't find 'thrice' in the following response\n{response.content}",
+                str(e),
+            )
         try:
             self.assertContains(response, "thrice", msg_prefix="abc")
         except AssertionError as e:
-            self.assertIn("abc: Couldn't find 'thrice' in response", str(e))
+            self.assertIn(
+                "abc: Couldn't find 'thrice' in the following response\n"
+                f"{response.content}",
+                str(e),
+            )
 
         try:
             self.assertContains(response, "thrice", 3)
         except AssertionError as e:
             self.assertIn(
-                "Found 0 instances of 'thrice' in response (expected 3)", str(e)
+                "Found 0 instances of 'thrice' (expected 3) in the following response\n"
+                f"{response.content}",
+                str(e),
             )
         try:
             self.assertContains(response, "thrice", 3, msg_prefix="abc")
         except AssertionError as e:
             self.assertIn(
-                "abc: Found 0 instances of 'thrice' in response (expected 3)", str(e)
+                "abc: Found 0 instances of 'thrice' (expected 3) in the following "
+                f"response\n{response.content}",
+                str(e),
             )
 
+        long_content = (
+            b"This is a very very very very very very very very long message which "
+            b"exceedes the max limit of truncation."
+        )
+        response = HttpResponse(long_content)
+        msg = f"Couldn't find 'thrice' in the following response\n{long_content}"
+        with self.assertRaisesMessage(AssertionError, msg):
+            self.assertContains(response, "thrice")
+
+        msg = (
+            "Found 1 instances of 'This' (expected 3) in the following response\n"
+            f"{long_content}"
+        )
+        with self.assertRaisesMessage(AssertionError, msg):
+            self.assertContains(response, "This", 3)
+
+        msg = f"'very' unexpectedly found in the following response\n{long_content}"
+        with self.assertRaisesMessage(AssertionError, msg):
+            self.assertNotContains(response, "very")
+
     def test_unicode_contains(self):
         "Unicode characters can be found in template context"
         # Regression test for #10183
diff --git a/tests/test_utils/tests.py b/tests/test_utils/tests.py
index 95526f768f..7df81650d5 100644
--- a/tests/test_utils/tests.py
+++ b/tests/test_utils/tests.py
@@ -985,12 +985,18 @@ class HTMLEqualTests(SimpleTestCase):
 
 class InHTMLTests(SimpleTestCase):
     def test_needle_msg(self):
-        msg = "False is not true : Couldn't find '<b>Hello</b>' in response"
+        msg = (
+            "False is not true : Couldn't find '<b>Hello</b>' in the following "
+            "response\n'<p>Test</p>'"
+        )
         with self.assertRaisesMessage(AssertionError, msg):
             self.assertInHTML("<b>Hello</b>", "<p>Test</p>")
 
     def test_msg_prefix(self):
-        msg = "False is not true : Prefix: Couldn't find '<b>Hello</b>' in response"
+        msg = (
+            "False is not true : Prefix: Couldn't find '<b>Hello</b>' in the following "
+            'response\n\'<input type="text" name="Hello" />\''
+        )
         with self.assertRaisesMessage(AssertionError, msg):
             self.assertInHTML(
                 "<b>Hello</b>",
@@ -1000,8 +1006,9 @@ class InHTMLTests(SimpleTestCase):
 
     def test_count_msg_prefix(self):
         msg = (
-            "2 != 1 : Prefix: Found 2 instances of '<b>Hello</b>' in response "
-            "(expected 1)"
+            "2 != 1 : Prefix: Found 2 instances of '<b>Hello</b>' (expected 1) in the "
+            "following response\n'<b>Hello</b><b>Hello</b>'"
+            ""
         )
         with self.assertRaisesMessage(AssertionError, msg):
             self.assertInHTML(
@@ -1011,6 +1018,38 @@ class InHTMLTests(SimpleTestCase):
                 msg_prefix="Prefix",
             )
 
+    def test_base(self):
+        haystack = "<p><b>Hello</b> <span>there</span>! Hi <span>there</span>!</p>"
+
+        self.assertInHTML("<b>Hello</b>", haystack=haystack)
+        msg = f"Couldn't find '<p>Howdy</p>' in the following response\n{haystack!r}"
+        with self.assertRaisesMessage(AssertionError, msg):
+            self.assertInHTML("<p>Howdy</p>", haystack)
+
+        self.assertInHTML("<span>there</span>", haystack=haystack, count=2)
+        msg = (
+            "Found 1 instances of '<b>Hello</b>' (expected 2) in the following response"
+            f"\n{haystack!r}"
+        )
+        with self.assertRaisesMessage(AssertionError, msg):
+            self.assertInHTML("<b>Hello</b>", haystack=haystack, count=2)
+
+    def test_long_haystack(self):
+        haystack = (
+            "<p>This is a very very very very very very very very long message which "
+            "exceedes the max limit of truncation.</p>"
+        )
+        msg = f"Couldn't find '<b>Hello</b>' in the following response\n{haystack!r}"
+        with self.assertRaisesMessage(AssertionError, msg):
+            self.assertInHTML("<b>Hello</b>", haystack)
+
+        msg = (
+            "Found 0 instances of '<b>This</b>' (expected 3) in the following response"
+            f"\n{haystack!r}"
+        )
+        with self.assertRaisesMessage(AssertionError, msg):
+            self.assertInHTML("<b>This</b>", haystack, 3)
+
 
 class JSONEqualTests(SimpleTestCase):
     def test_simple_equal(self):