feat(unstable): ability to `npm install` then `deno run main.ts` (#20967)

This PR adds a new unstable "bring your own node_modules" (BYONM)
functionality currently behind a `--unstable-byonm` flag (`"unstable":
["byonm"]` in a deno.json).

This enables users to run a separate install command (ex. `npm install`,
`pnpm install`) then run `deno run main.ts` and Deno will respect the
layout of the node_modules directory as setup by the separate install
command. It also works with npm/yarn/pnpm workspaces.

For this PR, the behaviour is opted into by specifying
`--unstable-byonm`/`"unstable": ["byonm"]`, but in the future we may
make this the default behaviour as outlined in
https://github.com/denoland/deno/issues/18967#issuecomment-1761248941

This is an extremely rough initial implementation. Errors are
terrible in this and the LSP requires frequent restarts. Improvements
will be done in follow up PRs.

1 files changed, 237 insertions, 0 deletions

diff --git a/cli/tests/integration/npm_tests.rs b/cli/tests/integration/npm_tests.rs
index ddbc79cec..c3fe2949c 100644
--- a/cli/tests/integration/npm_tests.rs
+++ b/cli/tests/integration/npm_tests.rs
@@ -2219,3 +2219,240 @@ itest!(require_resolve_url_paths {
   cwd: Some("npm/require_resolve_url/"),
   copy_temp_dir: Some("npm/require_resolve_url/"),
 });
+
+#[test]
+pub fn byonm_cjs_esm_packages() {
+  let test_context = TestContextBuilder::for_npm()
+    .env("DENO_UNSTABLE_BYONM", "1")
+    .use_temp_cwd()
+    .build();
+  let dir = test_context.temp_dir();
+  let run_npm = |args: &str| {
+    test_context
+      .new_command()
+      .name("npm")
+      .args(args)
+      .run()
+      .skip_output_check();
+  };
+
+  run_npm("init -y");
+  run_npm("install @denotest/esm-basic @denotest/cjs-default-export @denotest/dual-cjs-esm chalk@4 chai@4.3");
+
+  dir.write(
+    "main.ts",
+    r#"
+import { getValue, setValue } from "@denotest/esm-basic";
+
+setValue(2);
+console.log(getValue());
+
+import cjsDefault from "@denotest/cjs-default-export";
+console.log(cjsDefault.default());
+console.log(cjsDefault.named());
+
+import { getKind } from "@denotest/dual-cjs-esm";
+console.log(getKind());
+
+
+"#,
+  );
+  let output = test_context.new_command().args("run --check main.ts").run();
+  output
+    .assert_matches_text("Check file:///[WILDCARD]/main.ts\n2\n1\n2\nesm\n");
+
+  // should not have created the .deno directory
+  assert!(!dir.path().join("node_modules/.deno").exists());
+
+  // try chai
+  dir.write(
+    "chai.ts",
+    r#"import { expect } from "chai";
+
+    const timeout = setTimeout(() => {}, 0);
+    expect(timeout).to.be.a("number");
+    clearTimeout(timeout);"#,
+  );
+  test_context.new_command().args("run chai.ts").run();
+
+  // try chalk cjs
+  dir.write(
+    "chalk.ts",
+    "import chalk from 'chalk'; console.log(chalk.green('chalk cjs loads'));",
+  );
+  let output = test_context
+    .new_command()
+    .args("run --allow-read chalk.ts")
+    .run();
+  output.assert_matches_text("chalk cjs loads\n");
+
+  // try using an npm specifier for chalk that matches the version we installed
+  dir.write(
+    "chalk.ts",
+    "import chalk from 'npm:chalk@4'; console.log(chalk.green('chalk cjs loads'));",
+  );
+  let output = test_context
+    .new_command()
+    .args("run --allow-read chalk.ts")
+    .run();
+  output.assert_matches_text("chalk cjs loads\n");
+
+  // try with one that doesn't match the package.json
+  dir.write(
+    "chalk.ts",
+    "import chalk from 'npm:chalk@5'; console.log(chalk.green('chalk cjs loads'));",
+  );
+  let output = test_context
+    .new_command()
+    .args("run --allow-read chalk.ts")
+    .run();
+  output.assert_matches_text(
+    r#"error: Could not find a matching package for 'npm:chalk@5' in '[WILDCARD]package.json'. You must specify this as a package.json dependency when the node_modules folder is not managed by Deno.
+    at file:///[WILDCARD]chalk.ts:1:19
+"#);
+  output.assert_exit_code(1);
+}
+
+#[test]
+pub fn byonm_package_npm_specifier_not_installed_and_invalid_subpath() {
+  let test_context = TestContextBuilder::for_npm()
+    .env("DENO_UNSTABLE_BYONM", "1")
+    .use_temp_cwd()
+    .build();
+  let dir = test_context.temp_dir();
+  dir.path().join("package.json").write_json(&json!({
+    "dependencies": {
+      "chalk": "4",
+      "@denotest/conditional-exports-strict": "1"
+    }
+  }));
+  dir.write(
+    "main.ts",
+    "import chalk from 'npm:chalk'; console.log(chalk.green('hi'));",
+  );
+
+  // no npm install has been run, so this should give an informative error
+  let output = test_context.new_command().args("run main.ts").run();
+  output.assert_matches_text(
+    r#"error: Could not find '[WILDCARD]package.json'. Maybe run `npm install`?
+    at file:///[WILDCARD]/main.ts:1:19
+"#,
+  );
+  output.assert_exit_code(1);
+
+  // now test for an invalid sub path after doing an npm install
+  dir.write(
+    "main.ts",
+    "import 'npm:@denotest/conditional-exports-strict/test';",
+  );
+
+  test_context
+    .new_command()
+    .name("npm")
+    .args("install")
+    .run()
+    .skip_output_check();
+
+  let output = test_context.new_command().args("run main.ts").run();
+  output.assert_matches_text(
+    r#"error: Failed resolving package subpath './test' for '[WILDCARD]package.json'
+    at file:///[WILDCARD]/main.ts:1:8
+"#,
+  );
+  output.assert_exit_code(1);
+}
+
+#[test]
+pub fn byonm_npm_workspaces() {
+  let test_context = TestContextBuilder::for_npm().use_temp_cwd().build();
+  let dir = test_context.temp_dir();
+  dir.write(
+    "deno.json",
+    r#"{
+    "unstable": [
+      "byonm"
+    ]
+  }"#,
+  );
+
+  dir.write(
+    "package.json",
+    r#"{
+  "name": "my-workspace",
+  "workspaces": [
+    "project-a",
+    "project-b"
+  ]
+}
+"#,
+  );
+
+  let project_a_dir = dir.path().join("project-a");
+  project_a_dir.create_dir_all();
+  project_a_dir.join("package.json").write_json(&json!({
+    "name": "project-a",
+    "version": "1.0.0",
+    "main": "./index.js",
+    "type": "module",
+    "dependencies": {
+      "chai": "^4.2",
+      "project-b": "^1"
+    }
+  }));
+  project_a_dir.join("index.js").write(
+    r#"
+import { expect } from "chai";
+
+const timeout = setTimeout(() => {}, 0);
+expect(timeout).to.be.a("number");
+clearTimeout(timeout);
+
+export function add(a, b) {
+  return a + b;
+}
+"#,
+  );
+  project_a_dir
+    .join("index.d.ts")
+    .write("export function add(a: number, b: number): number;");
+
+  let project_b_dir = dir.path().join("project-b");
+  project_b_dir.create_dir_all();
+  project_b_dir.join("package.json").write_json(&json!({
+    "name": "project-b",
+    "version": "1.0.0",
+    "type": "module",
+    "dependencies": {
+      "@denotest/esm-basic": "^1.0",
+    }
+  }));
+  project_b_dir.join("main.ts").write(
+    r#"
+import { getValue, setValue } from "@denotest/esm-basic";
+
+setValue(5);
+console.log(getValue());
+
+import { add } from "project-a";
+console.log(add(1, 2));
+"#,
+  );
+
+  test_context
+    .new_command()
+    .name("npm")
+    .args("install")
+    .run()
+    .skip_output_check();
+
+  let output = test_context
+    .new_command()
+    .args("run ./project-b/main.ts")
+    .run();
+  output.assert_matches_text("5\n3\n");
+  let output = test_context
+    .new_command()
+    .args("check ./project-b/main.ts")
+    .run();
+  output.assert_matches_text("Check file:///[WILDCARD]/project-b/main.ts\n");
+}