5 files changed, 48 insertions, 0 deletions
diff --git a/tests/specs/npm/byonm_run_npm/__test__.jsonc b/tests/specs/npm/byonm_run_npm/__test__.jsonc
new file mode 100644
index 000000000..4f0b21b0f
--- /dev/null
+++ b/tests/specs/npm/byonm_run_npm/__test__.jsonc
@@ -0,0 +1,30 @@
+{
+  "tests": {
+    "not_in_deps": {
+      "steps": [{
+        "args": "run -A --quiet npm:cowsay moo",
+        "output": "not_in_deps.out"
+      }, {
+        // ensure it doesn't make any lockfile modifications and thus doesn't write to the lockfile
+        "args": [
+          "eval",
+          "try { Deno.statSync('deno.lock') } catch (e) { console.log(e instanceof Deno.errors.NotFound); }"
+        ],
+        "output": "true\n"
+      }]
+    },
+    "in_deps": {
+      "tempDir": true,
+      "steps": [{
+        "args": "install npm:cowsay",
+        "output": "[WILDCARD]"
+      }, {
+        "args": "run --allow-write overwrite.ts",
+        "output": "[WILDCARD]"
+      }, {
+        "args": "run -A npm:cowsay moo",
+        "output": "replaced\n"
+      }]
+    }
+  }
+}
diff --git a/tests/specs/npm/byonm_run_npm/deno.json b/tests/specs/npm/byonm_run_npm/deno.json
new file mode 100644
index 000000000..2c63c0851
--- /dev/null
+++ b/tests/specs/npm/byonm_run_npm/deno.json
@@ -0,0 +1,2 @@
+{
+}
diff --git a/tests/specs/npm/byonm_run_npm/not_in_deps.out b/tests/specs/npm/byonm_run_npm/not_in_deps.out
new file mode 100644
index 000000000..dc07eb43e
--- /dev/null
+++ b/tests/specs/npm/byonm_run_npm/not_in_deps.out
@@ -0,0 +1,8 @@
+ _____
+< moo >
+ -----
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||
diff --git a/tests/specs/npm/byonm_run_npm/overwrite.ts b/tests/specs/npm/byonm_run_npm/overwrite.ts
new file mode 100644
index 000000000..3749c5e4e
--- /dev/null
+++ b/tests/specs/npm/byonm_run_npm/overwrite.ts
@@ -0,0 +1,4 @@
+Deno.writeTextFileSync(
+  "node_modules/cowsay/cli.js",
+  "console.log('replaced');",
+);
diff --git a/tests/specs/npm/byonm_run_npm/package.json b/tests/specs/npm/byonm_run_npm/package.json
new file mode 100644
index 000000000..9664f260a
--- /dev/null
+++ b/tests/specs/npm/byonm_run_npm/package.json
@@ -0,0 +1,4 @@
+{
+  "dependencies": {
+  }
+}