Fix SURT edge case encoded query arg (#73)

ensure getSurt() preserves trailing '=' presence / absence if no value:
- '&x^' kept as '&x%5E' while '&x^=' kept as '&x%5E=' 
- fixes #70
- update formatting in testWARCParser.test.ts

src/lib/utils.ts

@@ -49,9 +49,19 @@ export function getSurt(url: string) {
       surt += urlObj.search;
       for (const [key, value] of urlObj.searchParams.entries()) {
         if (!value) {
+          // if no value set, by default the surt contains 'key='
+          // however, for compatibility, only want to add a trailing '='
+          // if original URL has it.
+          const keyEncoded = encodeURIComponent(key);
           const rx = new RegExp(`(?<=[&?])${rxEscape(key)}=(?=&|$)`);
+          // if original URL does *not* have trailing '=', attempt to remove it below
           if (!rx.exec(urlLower)) {
-            surt = surt.replace(rx, key);
+            // use URI encoded version to match the query arg if key is %-encoded
+            const rxEncoded =
+              key === keyEncoded
+                ? rx
+                : new RegExp(`(?<=[&?])${rxEscape(keyEncoded)}=(?=&|$)`);
+            surt = surt.replace(rxEncoded, keyEncoded);
           }
         }
       }

test/testUtils.test.ts

@@ -139,4 +139,15 @@ describe("utils", () => {
       "com,example)/some/path?*&a=b&c=d&z",
     );
   });
+
+  test("surt with %-encoded query, trailing = param", () => {
+    expect(getSurt("https://www.example.com/some/path?a=b&c=d&e^=&z")).toBe(
+      "com,example)/some/path?a=b&c=d&e%5E=&z",
+    );
+  });
+  test("surt with %-encoded query, no trailing = param", () => {
+    expect(getSurt("https://www.example.com/some/path?a=b&c=d&e^&z")).toBe(
+      "com,example)/some/path?a=b&c=d&e%5E&z",
+    );
+  });
 });

test/testWARCParser.test.ts

@@ -52,8 +52,8 @@ Multi-Line: Value1\r\n\
     Also This\r\n\
 \r\n\
 Body",
-      ])
-    )
+      ]),
+    ),
   );
   expect(result?.toString()).toBe(`\
 HTTP/1.0 200 OK\r
@@ -76,8 +76,8 @@ Content-Type: Value\r\n\
 Content-Length: 0\r\n\
 Bad: multi\nline\r\n\
 \r\n",
-      ])
-    )
+      ]),
+    ),
   );
   expect(result?.toString()).toBe(`HTTP/1.0 204 Empty\r
 Content-Type: Value\r
@@ -89,15 +89,15 @@ Bad: multi\r
 test("StatusAndHeaders test 3", async () => {
   const parser = new StatusAndHeadersParser();
   const result = await parser.parse(
-    new AsyncIterReader(getReader(["HTTP/1.0 204 None\r\n\r\n"]))
+    new AsyncIterReader(getReader(["HTTP/1.0 204 None\r\n\r\n"])),
   );
   expect(result?.toString()).toBe("HTTP/1.0 204 None\r\n");
 });
 
 test("StatusAndHeaders test empty", async () => {
   const parser = new StatusAndHeadersParser();
   const result = await parser.parse(
-    new AsyncIterReader(getReader(["\r\n\r\n"]))
+    new AsyncIterReader(getReader(["\r\n\r\n"])),
   );
   expect(result).toBe(null);
 });
@@ -178,7 +178,7 @@ text\r\n\
 software: recorder test\r\n\
 format: WARC File Format 1.0\r\n\
 json-metadata: {"foo": "bar"}\r\n\
-'
+',
   );
 
   // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- checked in expect
@@ -252,15 +252,15 @@ Content-Length: 0\r\n\
 
   expect(record.warcHeaders.protocol).toBe("WARC/1.0");
   expect(record.warcHeader("WARC-Record-ID")).toBe(
-    "<urn:uuid:12345678-feb0-11e6-8f83-68a86d1772ce>"
+    "<urn:uuid:12345678-feb0-11e6-8f83-68a86d1772ce>",
   );
   expect(record.warcType).toBe("revisit");
   expect(record.warcTargetURI).toBe("http://example.com/");
   expect(record.warcDate).toBe("2000-01-01T00:00:00Z");
   expect(record.warcRefersToTargetURI).toBe("http://example.com/foo");
   expect(record.warcRefersToDate).toBe("1999-01-01T00:00:00Z");
   expect(record.warcPayloadDigest).toBe(
-    "sha1:B6QJ6BNJ3R4B23XXMRKZKHLPGJY2VE4O"
+    "sha1:B6QJ6BNJ3R4B23XXMRKZKHLPGJY2VE4O",
   );
   expect(record.warcContentType).toBe("application/http; msgtype=response");
   expect(record.warcContentLength).toBe(0);
@@ -307,15 +307,15 @@ Foo: Bar\r\n\
   expect(record).not.toBeNull();
   expect(record.warcHeaders.protocol).toBe("WARC/1.0");
   expect(record.warcHeader("WARC-Record-ID")).toBe(
-    "<urn:uuid:12345678-feb0-11e6-8f83-68a86d1772ce>"
+    "<urn:uuid:12345678-feb0-11e6-8f83-68a86d1772ce>",
   );
   expect(record.warcType).toBe("revisit");
   expect(record.warcTargetURI).toBe("http://example.com/");
   expect(record.warcDate).toBe("2000-01-01T00:00:00Z");
   expect(record.warcRefersToTargetURI).toBe("http://example.com/foo");
   expect(record.warcRefersToDate).toBe("1999-01-01T00:00:00Z");
   expect(record.warcPayloadDigest).toBe(
-    "sha1:B6QJ6BNJ3R4B23XXMRKZKHLPGJY2VE4O"
+    "sha1:B6QJ6BNJ3R4B23XXMRKZKHLPGJY2VE4O",
   );
   expect(record.warcContentType).toBe("application/http; msgtype=response");
   expect(record.warcContentLength).toBe(54);
@@ -374,7 +374,7 @@ Foo: Bar\r\n\
 
   expect(record.warcHeaders.protocol).toBe("WARC/1.0");
   expect(record.warcHeader("WARC-Record-ID")).toBe(
-    "<urn:uuid:12345678-feb0-11e6-8f83-68a86d1772ce>"
+    "<urn:uuid:12345678-feb0-11e6-8f83-68a86d1772ce>",
   );
   expect(record.warcType).toBe("revisit");
   expect(record.warcContentLength).toBe(82);
@@ -542,7 +542,7 @@ test("warc1.1 serialize records match", async () => {
 
 test("chunked warc read", async () => {
   const input = fs.createReadStream(
-    get_warc_path("data/example-iana.org-chunked.warc")
+    get_warc_path("data/example-iana.org-chunked.warc"),
   );
 
   const parser = new WARCParser(input);
@@ -558,7 +558,7 @@ test("chunked warc read", async () => {
 
   // can't read raw data anymore
   await expect(async () => await record.readFully(false)).rejects.toThrow(
-    "WARC Record decoding already started, but requesting raw payload"
+    "WARC Record decoding already started, but requesting raw payload",
   );
 
   const text = await record.contentText();
@@ -568,15 +568,15 @@ test("chunked warc read", async () => {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any -- checking invalid type
   const busyRecord = record as any as { reader: LimitReader };
   await expect(async () => await busyRecord.reader.readFully()).rejects.toThrow(
-    "WARC Record decoding already started, but requesting raw payload"
+    "WARC Record decoding already started, but requesting raw payload",
   );
 
   expect(await record.readFully(true)).not.toBeNull();
 });
 
 test("no await catch errors", async () => {
   const input = fs.createReadStream(
-    get_warc_path("data/example-iana.org-chunked.warc")
+    get_warc_path("data/example-iana.org-chunked.warc"),
   );
 
   const parser = new WARCParser(input);
@@ -597,10 +597,10 @@ test("no await catch errors", async () => {
   const record1 = (await parser.parse())!;
   expect(record1).not.toBeNull();
   await expect(async () => await iter.next()).rejects.toThrow(
-    "Record already consumed.. Perhaps a promise was not awaited?"
+    "Record already consumed.. Perhaps a promise was not awaited?",
   );
   await expect(async () => await record0.readline()).rejects.toThrow(
-    "Record already consumed.. Perhaps a promise was not awaited?"
+    "Record already consumed.. Perhaps a promise was not awaited?",
   );
 
   let count = 0;
@@ -685,15 +685,15 @@ text\r\n\
         ["custom-header", "somevalue"],
         ["set-cookie", "greeting=hello"],
         ["set-cookie", "name=world"],
-      ])
+      ]),
     );
   } else {
     expect(JSON.stringify(headerEntries)).toBe(
       JSON.stringify([
         ["content-type", 'text/plain; charset="UTF-8"'],
         ["custom-header", "somevalue"],
         ["set-cookie", "greeting=hello, name=world"],
-      ])
+      ]),
     );
   }
 
@@ -718,7 +718,7 @@ text\r\n\
       ["content-type", 'text/plain; charset="UTF-8"'],
       ["custom-header", "somevalue"],
       ["unicode-header", "%F0%9F%93%81%20text%20%F0%9F%97%84%EF%B8%8F"],
-    ])
+    ]),
   );
 
   expect(decoder.decode(await record2.readFully())).toBe("more\ntext");