diff --git a/Cargo.lock b/Cargo.lock
index ff2615c..16e204f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc936419f96fa211c1b9166887b38e5e40b19958e5b895be7c1f93adec7071ac"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "anyhow"
 version = "1.0.65"
@@ -34,10 +43,12 @@ dependencies = [
  "ctrlc",
  "fs_extra",
  "libc",
+ "once_cell",
  "owo-colors",
  "prettyplease",
  "proc-macro2",
  "quote",
+ "regex",
  "rustfix",
  "serde",
  "serde_json",
@@ -241,6 +252,12 @@ dependencies = [
  "regex-automata",
 ]
 
+[[package]]
+name = "memchr"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+
 [[package]]
 name = "nix"
 version = "0.26.2"
@@ -265,9 +282,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.15.0"
+version = "1.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e82dad04139b71a90c080c8463fe0dc7902db5192d939bd0950f074d014339e1"
+checksum = "b7e5500299e16ebb147ae15a00a942af264cf3688f47923b8fc2cd5858f23ad3"
 
 [[package]]
 name = "os_str_bytes"
@@ -354,10 +371,12 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.6.0"
+version = "1.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c4eb3267174b8c6c2f654116623910a0fef09c4753f8dd83db29c48a0df988b"
+checksum = "8b1f693b24f6ac912f4893ef08244d70b6067480d2f1a46e950c9691e6749d1d"
 dependencies = [
+ "aho-corasick",
+ "memchr",
  "regex-syntax",
 ]
 
@@ -372,9 +391,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.27"
+version = "0.6.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a3f87b73ce11b1619a3c6332f45341e0047173771e8b8b73f87bfeefb7b56244"
+checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
 
 [[package]]
 name = "remove_dir_all"
diff --git a/Cargo.toml b/Cargo.toml
index b0a7de2..ff66d83 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -33,3 +33,5 @@ libc = "0.2.138"
 
 [dev-dependencies]
 fs_extra = "1.3.0"
+once_cell = "1.17.1"
+regex = "1.7.3"
diff --git a/full-tests/to-empty-main/src/main.rs b/full-tests/to-empty-main/src/main.rs
index d30ffc1..7f80c4e 100644
--- a/full-tests/to-empty-main/src/main.rs
+++ b/full-tests/to-empty-main/src/main.rs
@@ -1,7 +1,7 @@
-use std::collecions::HashMap;
+use std::collections::HashMap;
 
-/// ~REQUIRE-DELETED
-fn user(map: HashMap<(), ()>) {
+/// ~REQUIRE-DELETED user-fn
+fn user(mut map: HashMap<(), ()>) {
     map.insert((), ());
 }
 
diff --git a/tests/full_tests.rs b/tests/full_tests.rs
index 9997d35..4cbcc0b 100644
--- a/tests/full_tests.rs
+++ b/tests/full_tests.rs
@@ -1,4 +1,6 @@
 use anyhow::{ensure, Context, Result};
+use once_cell::sync::Lazy;
+use regex::Regex;
 use std::process::Command;
 use std::{
     fs,
@@ -7,6 +9,7 @@ use std::{
 };
 
 #[test]
+#[ignore = "unfinished"]
 fn full_tests() -> Result<()> {
     let path = Path::new(file!())
         .canonicalize()?
@@ -40,6 +43,9 @@ fn build(path: &Path) -> Result<()> {
 
     let proj_dir = tempdir.path().join(proj_dir).canonicalize()?;
 
+    let start_roots = get_roots(&proj_dir).context("getting initial roots")?;
+    eprintln!("Roots: {:?}", start_roots);
+
     let mut cmd = Command::new(cargo_minimize);
     cmd.current_dir(&proj_dir);
 
@@ -48,7 +54,46 @@ fn build(path: &Path) -> Result<()> {
     let out = cmd.output().context("spawning cargo-minimize")?;
     let stderr = String::from_utf8(out.stderr).unwrap();
 
-    // ensure!(out.status.success(), "Command failed:\n{stderr}",);
+    ensure!(out.status.success(), "Command failed:\n{stderr}");
+
+    let required_deleted = get_required_deleted(&proj_dir)?;
+
+    ensure!(
+        required_deleted.len() > 0,
+        "Some REQUIRE-DELETED have not been deleted: {required_deleted:?}"
+    );
 
     Ok(())
 }
+
+fn get_roots(path: &Path) -> Result<Vec<String>> {
+    static REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"~MINIMIZE-ROOT ([\w\-_]+)").unwrap());
+
+    grep(path, &REGEX)
+}
+
+fn get_required_deleted(path: &Path) -> Result<Vec<String>> {
+    static REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"~REQUIRE-DELETED ([\w\-_]+)").unwrap());
+
+    grep(path, &REGEX)
+}
+
+fn grep(path: &Path, regex: &Regex) -> Result<Vec<String>> {
+    let mut results = Vec::new();
+    let walk = walkdir::WalkDir::new(path);
+
+    for entry in walk {
+        let entry = entry?;
+        if !entry.metadata()?.is_file() {
+            continue;
+        }
+        let src = fs::read_to_string(entry.path())?;
+        let captures = regex.captures_iter(&src);
+        for cap in captures {
+            let root_name = cap.get(1).unwrap();
+            results.push(root_name.as_str().to_owned());
+        }
+    }
+
+    Ok(results)
+}