dev integrate and dev deintegrate

README.md

@@ -6,12 +6,9 @@ packages you need for different projects as you navigate in your shell.
 ## Installation
 
 ```sh
-echo 'eval "$(pkgx dev --shellcode)"' >> ~/.zshrc
+pkgx dev integrate
 ```
 
-We support bashlike shells (adapt the rc file above). Fish support is welcome,
-but I don’t understand Fish so please PR!
-
 > [!NOTE]
 >
 > `pkgx` is a required dependency.
@@ -20,6 +17,22 @@ but I don’t understand Fish so please PR!
 > brew install pkgxdev/made/pkgx || sh <(curl https://pkgx.sh)
 > ```
 
+> `pkgx dev integrate` looks for and edits known `shell.rc` files adding one
+> line:
+>
+> ```sh
+> eval "$(pkgx dev --shellcode)"
+> ```
+>
+> If you don’t trust us (good on you), then do a dry run first:
+>
+> ```sh
+> pkgx dev integrate --dry-run
+> ```
+
+> We support **Bash** and **Zsh**. We would love to support more shells. PRs
+> very welcome.
+
 > [!TIP]
 > If you like, preview the shellcode: `pkgx dev --shellcode`.
 

app.ts

@@ -8,6 +8,7 @@ import shellcode from "./src/shellcode().ts";
 import sniff from "./src/sniff.ts";
 import shell_escape from "./src/shell-escape.ts";
 import app_version from "./src/app-version.ts";
+import integrate from "./src/integrate.ts";
 
 switch (Deno.args[0]) {
   case "--help": {
@@ -25,6 +26,13 @@ switch (Deno.args[0]) {
     console.log(`dev ${app_version}`);
     Deno.exit(0);
     break; // deno lint insists
+  case "integrate":
+    await integrate("install", { dryrun: Deno.args[1] == "--dry-run" });
+    Deno.exit(0);
+    break;
+  case "deintegrate":
+    await integrate("uninstall", { dryrun: Deno.args[1] == "--dry-run" });
+    Deno.exit(0);
 }
 
 const snuff = await sniff(Path.cwd());

src/integrate.ts

@@ -0,0 +1,117 @@
+import readLines from "libpkgx/utils/read-lines.ts";
+import { readAll, writeAll } from "jsr:@std/io";
+import { Path, utils } from "libpkgx";
+const { flatmap } = utils;
+
+export default async function (
+  op: "install" | "uninstall",
+  { dryrun }: { dryrun: boolean },
+) {
+  let opd_at_least_once = false;
+  const encode = ((e) => e.encode.bind(e))(new TextEncoder());
+
+  const fopts = { read: true, ...dryrun ? {} : { write: true, create: true } };
+
+  here: for (const [file, line] of shells()) {
+    const fd = await Deno.open(file.string, fopts);
+    try {
+      let pos = 0;
+      for await (const readline of readLines(fd)) {
+        if (readline.trim().endsWith("# https://github.com/pkgxdev/dev")) {
+          if (op == "install") {
+            console.error("hook already integrated:", file);
+            continue here;
+          } else if (op == "uninstall") {
+            // we have to seek because readLines is buffered and thus the seek pos is probs already at the file end
+            await fd.seek(pos + readline.length + 1, Deno.SeekMode.Start);
+            const rest = await readAll(fd);
+
+            if (!dryrun) await fd.truncate(pos); // deno has no way I can find to truncate from the current seek position
+            await fd.seek(pos, Deno.SeekMode.Start);
+            if (!dryrun) await writeAll(fd, rest);
+
+            opd_at_least_once = true;
+            console.error("removed hook:", file);
+
+            continue here;
+          }
+        }
+
+        pos += readline.length + 1; // the +1 is because readLines() truncates it
+      }
+
+      if (op == "install") {
+        const byte = new Uint8Array(1);
+        if (pos) {
+          await fd.seek(0, Deno.SeekMode.End); // potentially the above didn't reach the end
+          while (true && pos > 0) {
+            await fd.seek(-1, Deno.SeekMode.Current);
+            await fd.read(byte);
+            if (byte[0] != 10) break;
+            await fd.seek(-1, Deno.SeekMode.Current);
+            pos -= 1;
+          }
+
+          if (!dryrun) {
+            await writeAll(
+              fd,
+              encode(`\n\n${line}  # https://github.com/pkgxdev/dev\n`),
+            );
+          }
+        }
+        opd_at_least_once = true;
+        console.error(`${file} << \`${line}\``);
+      }
+    } finally {
+      fd.close();
+    }
+  }
+  if (dryrun && opd_at_least_once) {
+    console.error(
+      "%cthis was a dry-run. %cnothing was changed.",
+      "color: #5f5fff",
+      "color: initial",
+    );
+  } else {switch (op) {
+      case "uninstall":
+        if (!opd_at_least_once) {
+          console.error("nothing to deintegrate found");
+        }
+        break;
+      case "install":
+        if (opd_at_least_once) {
+          console.log(
+            "now %crestart your terminal%c for `dev` hooks to take effect",
+            "color: #5f5fff",
+            "color: initial",
+          );
+        }
+    }}
+}
+
+function shells(): [Path, string][] {
+  const eval_ln = 'eval "$(pkgx dev --shellcode)"';
+
+  const zdotdir = flatmap(Deno.env.get("ZDOTDIR"), Path.abs) ?? Path.home();
+  const zshpair: [Path, string] = [zdotdir.join(".zshrc"), eval_ln];
+
+  const candidates: [Path, string][] = [
+    zshpair,
+    [Path.home().join(".bashrc"), eval_ln],
+    [Path.home().join(".bash_profile"), eval_ln],
+  ];
+
+  const viable_candidates = candidates.filter(([file]) => file.exists());
+
+  if (viable_candidates.length == 0) {
+    if (Deno.build.os == "darwin") {
+      /// macOS has no .zshrc by default and we want mac users to get a just works experience
+      return [zshpair];
+    } else {
+      console.error("no `.shellrc` files found");
+      Deno.exit(1);
+    }
+  }
+
+  return viable_candidates;
+}