feat(grep): treat - operand as standard input

.changeset/olive-donkeys-search.md

@@ -0,0 +1,5 @@
+---
+"just-bash": minor
+---
+
+Treat a `-` FILE operand in `grep` as standard input, matching GNU. `grep PATTERN -` now reads stdin instead of failing with "No such file or directory", stdin is labelled `(standard input)` in the multi-file prefix and in `-l`/`-L`/`-c` output, repeated `-` operands see the stream drained by the first one, and `-` is exempt from `-r` recursion and `--include`/`--exclude` filtering.

packages/just-bash/src/commands/grep/grep.stdin-operand.test.ts

@@ -0,0 +1,286 @@
+import { describe, expect, it } from "vitest";
+import { Bash } from "../../Bash.js";
+
+/**
+ * `-` as a FILE operand means standard input. GNU labels it
+ * `(standard input)` wherever a file name would appear, and treats it as a
+ * stream: only the first `-` of an invocation sees any content.
+ *
+ * Expectations verified against GNU grep 3.12.
+ */
+const files = {
+  "/f1.txt": "apple\nbanana\n",
+  "/f2.txt": "cherry\napple pie\n",
+};
+
+describe("grep - (stdin operand)", () => {
+  it("reads standard input for a lone - operand", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'apple\\n' | grep apple -");
+    expect(result.stdout).toBe("apple\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("prints no file-name prefix for a lone - operand", async () => {
+    const env = new Bash();
+    const result = await env.exec(
+      "printf 'x\\napple pie\\n' | grep -n apple -",
+    );
+    expect(result.stdout).toBe("2:apple pie\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("exits 1 when standard input has no match", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'zzz\\n' | grep apple -");
+    expect(result.stdout).toBe("");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(1);
+  });
+
+  it("exits 1 for empty standard input", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf '' | grep apple -");
+    expect(result.stdout).toBe("");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(1);
+  });
+
+  it("treats absent standard input as empty", async () => {
+    const env = new Bash();
+    const result = await env.exec("grep apple -");
+    expect(result.stdout).toBe("");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(1);
+  });
+
+  it("still accepts - as the PATTERN operand", async () => {
+    const env = new Bash({ files: { "/dash.txt": "a-b\nxy\n" } });
+    const result = await env.exec("grep - /dash.txt");
+    expect(result.stdout).toBe("a-b\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("accepts - after the -- option terminator", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'apple\\n' | grep -- apple -");
+    expect(result.stdout).toBe("apple\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("accepts - alongside -e", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'apple\\n' | grep -e apple -");
+    expect(result.stdout).toBe("apple\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+});
+
+describe("grep - (stdin operand) mixed with files", () => {
+  it("labels standard input in the multi-file prefix", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep apple /f1.txt - /f2.txt",
+    );
+    expect(result.stdout).toBe(
+      "/f1.txt:apple\n(standard input):apple stdin\n/f2.txt:apple pie\n",
+    );
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("keeps operand order when - comes first", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep apple - /f1.txt",
+    );
+    expect(result.stdout).toBe("(standard input):apple stdin\n/f1.txt:apple\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("labels standard input in -l output", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep -l apple /f1.txt - /f2.txt",
+    );
+    expect(result.stdout).toBe("/f1.txt\n(standard input)\n/f2.txt\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("labels standard input in -L output", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'zzz\\n' | grep -L apple /f1.txt - /f2.txt",
+    );
+    expect(result.stdout).toBe("(standard input)\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("labels standard input in -c output", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep -c apple /f1.txt - /f2.txt",
+    );
+    expect(result.stdout).toBe("/f1.txt:1\n(standard input):1\n/f2.txt:1\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("numbers standard input lines independently with -n", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'x\\napple stdin\\n' | grep -n apple /f1.txt - /f2.txt",
+    );
+    expect(result.stdout).toBe(
+      "/f1.txt:1:apple\n(standard input):2:apple stdin\n/f2.txt:2:apple pie\n",
+    );
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("suppresses the (standard input) label with -h", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep -h apple /f1.txt - /f2.txt",
+    );
+    expect(result.stdout).toBe("apple\napple stdin\napple pie\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("keeps the -l listing unprefixed by -h", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep -h -l apple /f1.txt -",
+    );
+    expect(result.stdout).toBe("/f1.txt\n(standard input)\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("reports a missing file but still searches standard input", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec("printf 'apple\\n' | grep apple /nope.txt -");
+    expect(result.stdout).toBe("(standard input):apple\n");
+    expect(result.stderr).toBe("grep: /nope.txt: No such file or directory\n");
+    expect(result.exitCode).toBe(2);
+  });
+
+  it("exits 0 for -q even when another operand is missing", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple\\n' | grep -q apple - /nope.txt",
+    );
+    expect(result.stdout).toBe("");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("ignores --include and --exclude for standard input", async () => {
+    const env = new Bash({ files });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep --include='*.txt' apple - /f1.txt",
+    );
+    expect(result.stdout).toBe("(standard input):apple stdin\n/f1.txt:apple\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+});
+
+describe("grep - (stdin operand) repeated", () => {
+  it("gives the second - an empty stream", async () => {
+    const env = new Bash();
+    const result = await env.exec(
+      "printf 'apple\\napple2\\n' | grep apple - -",
+    );
+    expect(result.stdout).toBe(
+      "(standard input):apple\n(standard input):apple2\n",
+    );
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("counts the second - as zero", async () => {
+    const env = new Bash();
+    const result = await env.exec(
+      "printf 'apple\\napple2\\n' | grep -c apple - -",
+    );
+    expect(result.stdout).toBe("(standard input):2\n(standard input):0\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("counts every - after the first as zero", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'apple\\n' | grep -c apple - - -");
+    expect(result.stdout).toBe(
+      "(standard input):1\n(standard input):0\n(standard input):0\n",
+    );
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("lists the drained - under -L", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'apple\\n' | grep -L apple - -");
+    expect(result.stdout).toBe("(standard input)\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("stops the first - at -m and leaves the second empty", async () => {
+    const env = new Bash();
+    const result = await env.exec(
+      "printf 'apple s1\\napple s2\\n' | grep -m1 apple - -",
+    );
+    expect(result.stdout).toBe("(standard input):apple s1\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+});
+
+describe("grep - (stdin operand) with -r", () => {
+  it("prints no prefix for a lone - under -r", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'apple stdin\\n' | grep -r apple -");
+    expect(result.stdout).toBe("apple stdin\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("prefixes when -r is given a directory alongside -", async () => {
+    const env = new Bash({ files: { "/sub/a.txt": "apple tree\n" } });
+    const result = await env.exec(
+      "printf 'apple stdin\\n' | grep -r apple - /sub",
+    );
+    expect(result.stdout).toBe(
+      "(standard input):apple stdin\n/sub/a.txt:apple tree\n",
+    );
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("lists both sources with -lr", async () => {
+    const env = new Bash({ files: { "/sub/a.txt": "apple tree\n" } });
+    const result = await env.exec("printf 'apple\\n' | grep -lr apple - /sub");
+    expect(result.stdout).toBe("(standard input)\n/sub/a.txt\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+
+  it("prefixes repeated - under -r", async () => {
+    const env = new Bash();
+    const result = await env.exec("printf 'apple\\n' | grep -r apple - -");
+    expect(result.stdout).toBe("(standard input):apple\n");
+    expect(result.stderr).toBe("");
+    expect(result.exitCode).toBe(0);
+  });
+});