Bug 1525326 - Remove backwards compatibility for custom unique ids for rules and stylesheets. r=gl

Since Firefox 67 tracked changes have unique identifiers as follows:
- ruleId => StyleRuleActor.actorID
- sourceId => StylesheetActor.actorID

Given that we're at Firefox 70 and beyond the window where we support connecting to servers older than 3 versions, this patch removes the backwards compatibility provided by methods to generate unique ids  based on attributes of the rule and stylesheet for the tracked change.

Differential Revision: https://phabricator.services.mozilla.com/D37591

--HG--
extra : moz-landing-system : lando

devtools/client/inspector/changes/reducers/changes.js

@@ -4,8 +4,6 @@
 
 "use strict";
 
-const { getSourceHash, getRuleHash } = require("../utils/changes-utils");
-
 const { RESET_CHANGES, TRACK_CHANGE } = require("../actions/index");
 
 /**
@@ -80,9 +78,7 @@ function createRule(ruleData, rules) {
           ];
         }
 
-        // Bug 1525326: Remove getRuleHash() in Firefox 70. Until then, we fallback
-        // to the custom hashing method if the server did not provide a rule with an id.
-        return rule.id || getRuleHash(rule);
+        return rule.id;
       })
       // Then, create new entries in the rules collection and assign dependencies.
       .map((ruleId, index, array) => {
@@ -216,11 +212,8 @@ const reducers = {
     state = cloneState(state);
 
     const { selector, ancestors, ruleIndex } = change;
-    // Bug 1525326: remove getSourceHash() and getRuleHash() in Firefox 70 after we no
-    // longer support old servers which do not implement the id for the rule and source.
-    const sourceId = change.source.id || getSourceHash(change.source);
-    const ruleId =
-      change.id || getRuleHash({ selectors: [selector], ancestors, ruleIndex });
+    const sourceId = change.source.id;
+    const ruleId = change.id;
 
     // Copy or create object identifying the source (styelsheet/element) for this change.
     const source = Object.assign({}, state[sourceId], change.source);

devtools/client/inspector/changes/utils/changes-utils.js

@@ -6,58 +6,6 @@
 
 const { getFormatStr, getStr } = require("./l10n");
 
-/**
- * Generate a hash that uniquely identifies a stylesheet or element style attribute.
- *
- * @param {Object} source
- *        Information about a stylesheet or element style attribute:
- *        {
- *          type:  {String}
- *                 One of "stylesheet", "inline" or "element".
- *          index: {Number|String}
- *                 Position of the styleshet in the list of stylesheets in the document.
- *                 If `type` is "element", `index` is the generated selector which
- *                 uniquely identifies the element in the document.
- *          href:  {String}
- *                 URL of the stylesheet or of the document when `type` is "element" or
- *                 "inline".
- *        }
- * @return {String}
- */
-function getSourceHash(source) {
-  const { type, index, href } = source;
-
-  return `${type}${index}${href}`;
-}
-
-/**
- * Generate a hash that uniquely identifies a CSS rule.
- *
- * @param {Object} ruleData
- *        Information about a CSS rule:
- *        {
- *          selectors: {Array}
- *                     Array of CSS selector text
- *          ancestors: {Array}
- *                     Flattened CSS rule tree of the rule's ancestors with the root rule
- *                     at the beginning of the array and the leaf rule at the end.
- *          ruleIndex: {Array}
- *                     Indexes of each ancestor rule within its parent rule.
- *        }
- * @return {String}
- */
-function getRuleHash(ruleData) {
-  const { selectors = [], ancestors = [], ruleIndex } = ruleData;
-  const atRules = ancestors.reduce((acc, rule) => {
-    acc += `${rule.typeName} ${rule.conditionText ||
-      rule.name ||
-      rule.keyText}`;
-    return acc;
-  }, "");
-
-  return `${atRules}${selectors}${ruleIndex}`;
-}
-
 /**
  * Get a human-friendly style source path to display in the Changes panel.
  * For element inline styles, return a string indicating that.
@@ -91,5 +39,3 @@ function getSourceForDisplay(source) {
 }
 
 module.exports.getSourceForDisplay = getSourceForDisplay;
-module.exports.getSourceHash = getSourceHash;
-module.exports.getRuleHash = getRuleHash;