hash_util: Move enc/decodeHashComponent to shared.

Moves the encodeHashComponent and decodeHashComponent functions out of
hash_util and into internal_url which belongs to shared. This is to
accommodate sharing of this code with mobile or any other codebases that
do not wish to duplicate logic.

frontend_tests/node_tests/hash_util.js

@@ -25,17 +25,7 @@ const frontend = {
 stream_data.add_sub(frontend);
 
 run_test("hash_util", () => {
-    // Test encodeHashComponent
-    const str = "https://www.zulipexample.com";
-    const result1 = hash_util.encodeHashComponent(str);
-    assert.equal(result1, "https.3A.2F.2Fwww.2Ezulipexample.2Ecom");
-
-    // Test decodeHashComponent
-    const result2 = hash_util.decodeHashComponent(result1);
-    assert.equal(result2, str);
-
     // Test encode_operand and decode_operand
-
     function encode_decode_operand(operator, operand, expected_val) {
         const encode_result = hash_util.encode_operand(operator, operand);
         assert.equal(encode_result, expected_val);

frontend_tests/node_tests/internal_url.js

@@ -0,0 +1,22 @@
+"use strict";
+
+const {strict: assert} = require("assert");
+
+const {zrequire} = require("../zjsunit/namespace");
+const {run_test} = require("../zjsunit/test");
+
+const internal_url = zrequire("../shared/js/internal_url");
+
+run_test("test encodeHashComponent", () => {
+    const decoded = "https://www.zulipexample.com";
+    const encoded = "https.3A.2F.2Fwww.2Ezulipexample.2Ecom";
+    const result = internal_url.encodeHashComponent(decoded);
+    assert.equal(result, encoded);
+});
+
+run_test("test decodeHashComponent", () => {
+    const decoded = "https://www.zulipexample.com";
+    const encoded = "https.3A.2F.2Fwww.2Ezulipexample.2Ecom";
+    const result = internal_url.decodeHashComponent(encoded);
+    assert.equal(result, decoded);
+});

static/js/hash_util.js

@@ -1,3 +1,5 @@
+import * as internal_url from "../shared/js/internal_url";
+
 import * as people from "./people";
 import * as stream_data from "./stream_data";
 
@@ -26,20 +28,6 @@ export function get_current_hash_section() {
     return get_hash_section(window.location.hash);
 }
 
-const hashReplacements = new Map([
-    ["%", "."],
-    ["(", ".28"],
-    [")", ".29"],
-    [".", ".2E"],
-]);
-
-// Some browsers zealously URI-decode the contents of
-// window.location.hash.  So we hide our URI-encoding
-// by replacing % with . (like MediaWiki).
-export function encodeHashComponent(str) {
-    return encodeURIComponent(str).replace(/[%().]/g, (matched) => hashReplacements.get(matched));
-}
-
 export function build_reload_url() {
     let hash = window.location.hash;
     if (hash.length !== 0 && hash[0] === "#") {
@@ -60,7 +48,7 @@ export function encode_operand(operator, operand) {
         return encode_stream_name(operand);
     }
 
-    return encodeHashComponent(operand);
+    return internal_url.encodeHashComponent(operand);
 }
 
 export function encode_stream_id(stream_id) {
@@ -68,7 +56,7 @@ export function encode_stream_id(stream_id) {
     // URI encoding piece
     const slug = stream_data.id_to_slug(stream_id);
 
-    return encodeHashComponent(slug);
+    return internal_url.encodeHashComponent(slug);
 }
 
 export function encode_stream_name(operand) {
@@ -76,17 +64,7 @@ export function encode_stream_name(operand) {
     // URI encoding piece
     operand = stream_data.name_to_slug(operand);
 
-    return encodeHashComponent(operand);
-}
-
-export function decodeHashComponent(str) {
-    // This fails for URLs containing
-    // foo.foo or foo%foo due to our fault in special handling
-    // of such characters when encoding. This can also,
-    // fail independent of our fault, so just tell the user
-    // that the URL is invalid.
-    // TODO: Show possible valid URLs to the user.
-    return decodeURIComponent(str.replace(/\./g, "%"));
+    return internal_url.encodeHashComponent(operand);
 }
 
 export function decode_operand(operator, operand) {
@@ -97,7 +75,7 @@ export function decode_operand(operator, operand) {
         }
     }
 
-    operand = decodeHashComponent(operand);
+    operand = internal_url.decodeHashComponent(operand);
 
     if (operator === "stream") {
         return stream_data.slug_to_name(operand);
@@ -111,7 +89,12 @@ export function by_stream_uri(stream_id) {
 }
 
 export function by_stream_topic_uri(stream_id, topic) {
-    return "#narrow/stream/" + encode_stream_id(stream_id) + "/topic/" + encodeHashComponent(topic);
+    return (
+        "#narrow/stream/" +
+        encode_stream_id(stream_id) +
+        "/topic/" +
+        internal_url.encodeHashComponent(topic)
+    );
 }
 
 // Encodes an operator list into the
@@ -132,7 +115,7 @@ export function operators_to_hash(operators) {
             hash +=
                 "/" +
                 sign +
-                encodeHashComponent(operator) +
+                internal_url.encodeHashComponent(operator) +
                 "/" +
                 encode_operand(operator, operand);
         }
@@ -166,7 +149,7 @@ export function by_conversation_and_time_uri(message) {
         "/" +
         window.location.pathname.split("/")[1];
 
-    const suffix = "/near/" + encodeHashComponent(message.id);
+    const suffix = "/near/" + internal_url.encodeHashComponent(message.id);
 
     if (message.type === "stream") {
         return absolute_url + by_stream_topic_uri(message.stream_id, message.topic) + suffix;
@@ -176,7 +159,7 @@ export function by_conversation_and_time_uri(message) {
 }
 
 export function stream_edit_uri(sub) {
-    const hash = `#streams/${sub.stream_id}/${encodeHashComponent(sub.name)}`;
+    const hash = `#streams/${sub.stream_id}/${internal_url.encodeHashComponent(sub.name)}`;
     return hash;
 }
 
@@ -193,7 +176,7 @@ export function parse_narrow(hash) {
     for (i = 1; i < hash.length; i += 2) {
         // We don't construct URLs with an odd number of components,
         // but the user might write one.
-        let operator = decodeHashComponent(hash[i]);
+        let operator = internal_url.decodeHashComponent(hash[i]);
         // Do not parse further if empty operator encountered.
         if (operator === "") {
             break;

static/js/hashchange.js

@@ -1,6 +1,5 @@
 import $ from "jquery";
 
-import {$t_html} from "./i18n";
 import * as about_zulip from "./about_zulip";
 import * as admin from "./admin";
 import * as blueslip from "./blueslip";
@@ -8,6 +7,7 @@ import * as browser_history from "./browser_history";
 import * as drafts from "./drafts";
 import * as floating_recipient_bar from "./floating_recipient_bar";
 import * as hash_util from "./hash_util";
+import {$t_html} from "./i18n";
 import * as info_overlay from "./info_overlay";
 import * as invite from "./invite";
 import * as message_lists from "./message_lists";
@@ -25,8 +25,8 @@ import * as settings_toggle from "./settings_toggle";
 import * as spectators from "./spectators";
 import * as stream_settings_ui from "./stream_settings_ui";
 import * as top_left_corner from "./top_left_corner";
-import * as ui_util from "./ui_util";
 import * as ui_report from "./ui_report";
+import * as ui_util from "./ui_util";
 import {user_settings} from "./user_settings";
 
 // Read https://zulip.readthedocs.io/en/latest/subsystems/hashchange-system.html
@@ -138,13 +138,8 @@ function do_hashchange_normal(from_reload) {
         case "#narrow": {
             maybe_hide_recent_topics();
             ui_util.change_tab_to("#message_feed_container");
-            let operators = undefined;
+            let operators;
             try {
-                // This fails for URLs containing
-                // foo.foo or foo%foo due to our fault in special handling
-                // of such characters when encoding. This can also,
-                // fail independent of our fault, so just tell the user
-                // that the URL is invalid.
                 // TODO: Show possible valid URLs to the user.
                 operators = hash_util.parse_narrow(hash);
             } catch {

static/shared/js/internal_url.js

@@ -0,0 +1,22 @@
+const hashReplacements = new Map([
+    ["%", "."],
+    ["(", ".28"],
+    [")", ".29"],
+    [".", ".2E"],
+]);
+
+// Some browsers zealously URI-decode the contents of
+// window.location.hash.  So we hide our URI-encoding
+// by replacing % with . (like MediaWiki).
+export function encodeHashComponent(str) {
+    return encodeURIComponent(str).replace(/[%().]/g, (matched) => hashReplacements.get(matched));
+}
+
+export function decodeHashComponent(str) {
+    // This fails for URLs containing
+    // foo.foo or foo%foo due to our fault in special handling
+    // of such characters when encoding. This can also,
+    // fail independent of our fault.
+    // Here we let the calling code handle the exception.
+    return decodeURIComponent(str.replace(/\./g, "%"));
+}

zerver/lib/url_encoding.py

@@ -6,8 +6,8 @@ from zerver.models import Realm, Stream, UserProfile
 
 
 def hash_util_encode(string: str) -> str:
-    # Do the same encoding operation as hash_util.encodeHashComponent on the
-    # frontend.
+    # Do the same encoding operation as shared internal_url.encodeHashComponent
+    # on the frontend.
     # `safe` has a default value of "/", but we want those encoded, too.
     return quote(string, safe=b"").replace(".", "%2E").replace("%", ".")