PatchHelper, a tool to help you write patches (#182)

1 files changed, 279 insertions, 0 deletions

diff --git a/src/components/PatchHelper.tsx b/src/components/PatchHelper.tsx
new file mode 100644
index 0000000..b490051
--- /dev/null
+++ b/src/components/PatchHelper.tsx
@@ -0,0 +1,279 @@
+/*
+ * Vencord, a modification for Discord's desktop app
+ * Copyright (c) 2022 Vendicated and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import { makeCodeblock } from "../utils";
+import { debounce } from "../utils/debounce";
+import { Button, Clipboard, Forms, Margins, Parser, React, Switch, TextInput } from "../webpack/common";
+import { search } from "../webpack/webpack";
+import { CheckedTextInput } from "./CheckedTextInput";
+import ErrorBoundary from "./ErrorBoundary";
+
+// Do not include diff in non dev builds (side effects import)
+if (IS_DEV) {
+    var differ = require("diff") as typeof import("diff");
+}
+
+const findCandidates = debounce(function ({ find, setModule, setError }) {
+    const candidates = search(find);
+    const keys = Object.keys(candidates);
+    const len = keys.length;
+    if (len === 0)
+        setError("No match. Perhaps that module is lazy loaded?");
+    else if (len !== 1)
+        setError("Multiple matches. Please refine your filter");
+    else
+        setModule([keys[0], candidates[keys[0]]]);
+});
+
+function ReplacementComponent({ module, match, replacement, setReplacementError }) {
+    const [id, fact] = module;
+    const [compileResult, setCompileResult] = React.useState<[boolean, string]>();
+
+    const [patchedCode, matchResult, diff] = React.useMemo(() => {
+        const src: string = fact.toString().replaceAll("\n", "");
+        try {
+            var patched = src.replace(match, replacement);
+            setReplacementError(void 0);
+        } catch (e) {
+            setReplacementError((e as Error).message);
+            return ["", [], []];
+        }
+        const m = src.match(match);
+        return [patched, m, makeDiff(src, patched, m)];
+    }, [id, match, replacement]);
+
+    function makeDiff(original: string, patched: string, match: RegExpMatchArray | null) {
+        if (!match || original === patched) return null;
+
+        const changeSize = patched.length - original.length;
+
+        // Use 200 surrounding characters of context
+        const start = Math.max(0, match.index! - 200);
+        const end = Math.min(original.length, match.index! + match[0].length + 200);
+        // (changeSize may be negative)
+        const endPatched = end + changeSize;
+
+        const context = original.slice(start, end);
+        const patchedContext = patched.slice(start, endPatched);
+
+        return differ.diffWordsWithSpace(context, patchedContext);
+    }
+
+    function renderMatch() {
+        if (!matchResult)
+            return <Forms.FormText>Regex doesn't match!</Forms.FormText>;
+
+        const fullMatch = matchResult[0] ? makeCodeblock(matchResult[0], "js") : "";
+        const groups = matchResult.length > 1
+            ? makeCodeblock(matchResult.slice(1).map((g, i) => `Group ${i}: ${g}`).join("\n"), "yml")
+            : "";
+
+        return (
+            <>
+                {Parser.parse(fullMatch)}
+                {Parser.parse(groups)}
+            </>
+        );
+    }
+
+    function renderDiff() {
+        return diff?.map(p => {
+            const color = p.added ? "lime" : p.removed ? "red" : "grey";
+            return <span style={{ color }}>{p.value}</span>;
+        });
+    }
+
+    return (
+        <>
+            <Forms.FormTitle>Module {id}</Forms.FormTitle>
+
+            {!!matchResult?.[0]?.length && (
+                <>
+                    <Forms.FormTitle>Match</Forms.FormTitle>
+                    {renderMatch()}
+                </>)
+            }
+
+            {!!diff?.length && (
+                <>
+                    <Forms.FormTitle>Diff</Forms.FormTitle>
+                    {renderDiff()}
+                </>
+            )}
+
+            {!!diff?.length && (
+                <Button className={Margins.marginTop20} onClick={() => {
+                    try {
+                        Function(patchedCode);
+                        setCompileResult([true, "Compiled successfully"]);
+                    } catch (err) {
+                        setCompileResult([false, (err as Error).message]);
+                    }
+                }}>Compile</Button>
+            )}
+
+            {compileResult &&
+                <Forms.FormText style={{ color: compileResult[0] ? "var(--text-positive)" : "var(--text-danger)" }}>
+                    {compileResult[1]}
+                </Forms.FormText>
+            }
+        </>
+    );
+}
+
+function ReplacementInput({ replacement, setReplacement, replacementError }) {
+    const [isFunc, setIsFunc] = React.useState(false);
+    const [error, setError] = React.useState<string>();
+
+    function onChange(v: string) {
+        setError(void 0);
+
+        if (isFunc) {
+            try {
+                const func = (0, eval)(v);
+                if (typeof func === "function")
+                    setReplacement(() => func);
+                else
+                    setError("Replacement must be a function");
+            } catch (e) {
+                setReplacement(v);
+                setError((e as Error).message);
+            }
+        } else {
+            setReplacement(v);
+        }
+    }
+
+    React.useEffect(
+        () => void (isFunc ? onChange(replacement) : setError(void 0)),
+        [isFunc]
+    );
+
+    return (
+        <>
+            <Forms.FormTitle>replacement</Forms.FormTitle>
+            <TextInput
+                value={replacement?.toString()}
+                onChange={onChange}
+                error={error ?? replacementError}
+            />
+
+            <Switch
+                className={Margins.marginTop8}
+                value={isFunc}
+                onChange={setIsFunc}
+                note="'replacement' will be evaled if this is toggled"
+                hideBorder={true}
+            >
+                Treat as Function
+            </Switch>
+        </>
+    );
+}
+
+function PatchHelper() {
+    const [find, setFind] = React.useState<string>("");
+    const [match, setMatch] = React.useState<string>("");
+    const [replacement, setReplacement] = React.useState<string | Function>("");
+
+    const [replacementError, setReplacementError] = React.useState<string>();
+
+    const [module, setModule] = React.useState<[number, Function]>();
+    const [findError, setFindError] = React.useState<string>();
+
+    const code = React.useMemo(() => {
+        return `
+{
+    find: ${JSON.stringify(find)},
+    replacement: {
+        match: /${match.replace(/(?<!\\)\//g, "\\/")}/,
+        replacement: ${typeof replacement === "function" ? replacement.toString() : JSON.stringify(replacement)}
+    }
+}
+        `.trim();
+    }, [find, match, replacement]);
+
+    function onFindChange(v: string) {
+        setFindError(void 0);
+        setFind(v);
+        if (v.length) {
+            findCandidates({ find: v, setModule, setError: setFindError });
+        }
+    }
+
+    function onMatchChange(v: string) {
+        try {
+            new RegExp(v);
+            setFindError(void 0);
+            setMatch(v);
+        } catch (e: any) {
+            setFindError((e as Error).message);
+        }
+    }
+
+    return (
+        <>
+            <Forms.FormTitle>find</Forms.FormTitle>
+            <TextInput
+                type="text"
+                value={find}
+                onChange={onFindChange}
+                error={findError}
+            />
+
+            <Forms.FormTitle>match</Forms.FormTitle>
+            <CheckedTextInput
+                value={match}
+                onChange={onMatchChange}
+                validate={v => {
+                    try {
+                        return (new RegExp(v), true);
+                    } catch (e) {
+                        return (e as Error).message;
+                    }
+                }}
+            />
+
+            <ReplacementInput
+                replacement={replacement}
+                setReplacement={setReplacement}
+                replacementError={replacementError}
+            />
+
+            <Forms.FormDivider />
+            {module && (
+                <ReplacementComponent
+                    module={module}
+                    match={new RegExp(match)}
+                    replacement={replacement}
+                    setReplacementError={setReplacementError}
+                />
+            )}
+
+            {!!(find && match && replacement) && (
+                <>
+                    <Forms.FormTitle className={Margins.marginTop20}>Code</Forms.FormTitle>
+                    {Parser.parse(makeCodeblock(code, "ts"))}
+                    <Button onClick={() => Clipboard.copy(code)}>Copy to Clipboard</Button>
+                </>
+            )}
+        </>
+    );
+}
+
+export default IS_DEV ? ErrorBoundary.wrap(PatchHelper) : null;