Patcher: More useful errors with code diffs (#177)

* Patcher: More useful errors with code diffs

* Nicer log formatting

* PluginCards: ellipsises

4 files changed, 79 insertions, 14 deletions

diff --git a/src/components/PluginSettings/index.tsx b/src/components/PluginSettings/index.tsx
index 6ad9750..1a2e78f 100644
--- a/src/components/PluginSettings/index.tsx
+++ b/src/components/PluginSettings/index.tsx
@@ -145,7 +145,19 @@ function PluginCard({ plugin, disabled, onRestartNeeded, onMouseEnter, onMouseLe
                 onChange={toggleEnabled}
                 disabled={disabled}
                 value={isEnabled()}
-                note={<Text variant="text-md/normal" style={{ height: 40, overflow: "hidden" }}>{plugin.description}</Text>}
+                note={<Text variant="text-md/normal" style={{
+                    height: 40,
+                    overflow: "hidden",
+                    // mfw css is so bad you need whatever this is to get multi line overflow ellipsis to work
+                    textOverflow: "ellipsis",
+                    display: "-webkit-box", // firefox users will cope (it doesn't support it)
+                    WebkitLineClamp: 2,
+                    lineClamp: 2,
+                    WebkitBoxOrient: "vertical",
+                    boxOrient: "vertical"
+                }}>
+                    {plugin.description}
+                </Text>}
                 hideBorder={true}
             >
                 <Flex style={{ marginTop: "auto", width: "100%", height: "100%", alignItems: "center" }}>
diff --git a/src/globals.d.ts b/src/globals.d.ts
index 071bca2..2872f62 100644
--- a/src/globals.d.ts
+++ b/src/globals.d.ts
@@ -32,6 +32,7 @@ declare global {
      * replace: `${IS_WEB}?foo:bar`
      */
     export var IS_WEB: boolean;
+    export var IS_DEV: boolean;
     export var IS_STANDALONE: boolean;
 
     export var VencordNative: typeof import("./VencordNative").default;
diff --git a/src/utils/logger.ts b/src/utils/logger.ts
index 309f4db..24cd2c8 100644
--- a/src/utils/logger.ts
+++ b/src/utils/logger.ts
@@ -17,11 +17,23 @@
 */
 
 export default class Logger {
+    /**
+     * Returns the console format args for a title with the specified background colour and black text
+     * @param color Background colour
+     * @param title Text
+     * @returns Array. Destructure this into {@link Logger}.errorCustomFmt or console.log
+     *
+     * @example logger.errorCustomFmt(...Logger.makeTitleElements("white", "Hello"), "World");
+     */
+    static makeTitle(color: string, title: string): [string, ...string[]] {
+        return ["%c %c %s ", "", `background: ${color}; color: black; font-weight: bold; border-radius: 5px;`, title];
+    }
+
     constructor(public name: string, public color: string) { }
 
-    private _log(level: "log" | "error" | "warn" | "info" | "debug", levelColor: string, args: any[]) {
+    private _log(level: "log" | "error" | "warn" | "info" | "debug", levelColor: string, args: any[], customFmt = "") {
         console[level](
-            `%c Vencord %c %c ${this.name} `,
+            `%c Vencord %c %c ${this.name} ${customFmt}`,
             `background: ${levelColor}; color: black; font-weight: bold; border-radius: 5px;`,
             "",
             `background: ${this.color}; color: black; font-weight: bold; border-radius: 5px;`
@@ -41,6 +53,10 @@ export default class Logger {
         this._log("error", "#e78284", args);
     }
 
+    public errorCustomFmt(fmt: string, ...args: any[]) {
+        this._log("error", "#e78284", args, fmt);
+    }
+
     public warn(...args: any[]) {
         this._log("warn", "#e5c890", args);
     }
diff --git a/src/webpack/patchWebpack.ts b/src/webpack/patchWebpack.ts
index f679f3a..5596730 100644
--- a/src/webpack/patchWebpack.ts
+++ b/src/webpack/patchWebpack.ts
@@ -41,7 +41,7 @@ Object.defineProperty(window, WEBPACK_CHUNK, {
 });
 
 function patchPush() {
-    function handlePush(chunk) {
+    function handlePush(chunk: any) {
         try {
             const modules = chunk[1];
             const { subscriptions, listeners } = Vencord.Webpack;
@@ -56,7 +56,7 @@ function patchPush() {
                 // Additionally, `[actual newline]` is one less char than "\n", so if Discord
                 // ever targets newer browsers, the minifier could potentially use this trick and
                 // cause issues.
-                let code = mod.toString().replaceAll("\n", "");
+                let code: string = mod.toString().replaceAll("\n", "");
                 const originalMod = mod;
                 const patchedBy = new Set();
 
@@ -90,6 +90,7 @@ function patchPush() {
                             logger.error("Error in webpack listener", err);
                         }
                     }
+
                     for (const [filter, callback] of subscriptions) {
                         try {
                             if (filter(exports)) {
@@ -113,45 +114,80 @@ function patchPush() {
                         }
                     }
                 };
+
                 modules[id].toString = () => mod.toString();
                 modules[id].original = originalMod;
 
                 for (let i = 0; i < patches.length; i++) {
                     const patch = patches[i];
                     if (patch.predicate && !patch.predicate()) continue;
+
                     if (code.includes(patch.find)) {
                         patchedBy.add(patch.plugin);
+
                         // @ts-ignore we change all patch.replacement to array in plugins/index
                         for (const replacement of patch.replacement) {
                             const lastMod = mod;
                             const lastCode = code;
+
                             try {
                                 const newCode = code.replace(replacement.match, replacement.replace);
                                 if (newCode === code) {
-                                    logger.warn(`Patch by ${patch.plugin} had no effect: ${replacement.match}`);
-                                    logger.debug("Function Source:\n", code);
+                                    logger.warn(`Patch by ${patch.plugin} had no effect (Module id is ${id}): ${replacement.match}`);
+                                    if (IS_DEV) {
+                                        logger.debug("Function Source:\n", code);
+                                    }
                                 } else {
                                     code = newCode;
                                     mod = (0, eval)(`// Webpack Module ${id} - Patched by ${[...patchedBy].join(", ")}\n${newCode}\n//# sourceURL=WebpackModule${id}`);
                                 }
                             } catch (err) {
-                                // TODO - More meaningful errors. This probably means moving away from string.replace
-                                // in favour of manual matching. Then cut out the context and log some sort of
-                                // diff
-                                logger.error("Failed to apply patch of", patch.plugin, err);
-                                logger.debug("Original Source\n", lastCode);
-                                logger.debug("Patched Source\n", code);
+                                logger.error(`Failed to apply patch ${replacement.match} of ${patch.plugin} to ${id}:\n`, err);
+
+                                if (IS_DEV) {
+                                    const changeSize = code.length - lastCode.length;
+                                    const match = lastCode.match(replacement.match)!;
+
+                                    // Use 200 surrounding characters of context
+                                    const start = Math.max(0, match.index! - 200);
+                                    const end = Math.min(lastCode.length, match.index! + match[0].length + 200);
+                                    // (changeSize may be negative)
+                                    const endPatched = end + changeSize;
+
+                                    const context = lastCode.slice(start, end);
+                                    const patchedContext = code.slice(start, endPatched);
+
+                                    // inline require to avoid including it in !IS_DEV builds
+                                    const diff = (require("diff") as typeof import("diff")).diffWordsWithSpace(context, patchedContext);
+                                    let fmt = "%c %s ";
+                                    const elements = [] as string[];
+                                    for (const d of diff) {
+                                        const color = d.removed
+                                            ? "red"
+                                            : d.added
+                                                ? "lime"
+                                                : "grey";
+                                        fmt += "%c%s";
+                                        elements.push("color:" + color, d.value);
+                                    }
+
+                                    logger.errorCustomFmt(...Logger.makeTitle("white", "Before"), context);
+                                    logger.errorCustomFmt(...Logger.makeTitle("white", "After"), context);
+                                    const [titleFmt, ...titleElements] = Logger.makeTitle("white", "Diff");
+                                    logger.errorCustomFmt(titleFmt + fmt, ...titleElements, ...elements);
+                                }
                                 code = lastCode;
                                 mod = lastMod;
                                 patchedBy.delete(patch.plugin);
                             }
                         }
+
                         if (!patch.all) patches.splice(i--, 1);
                     }
                 }
             }
         } catch (err) {
-            logger.error("oopsie", err);
+            logger.error("Error in handlePush", err);
         }
 
         return handlePush.original.call(window[WEBPACK_CHUNK], chunk);