fix(analyze): detect replacement token in xargs env assignments

The hasDynamicReplacement check now also looks at envAssignments for the
replacement token, catching cases like
where the token appears in an environment variable value rather than a
direct argument.

Author: kenryu42

dist/bin/cc-safety-net.js

@@ -4187,7 +4187,7 @@ function analyzeXargs(tokens, context) {
   }
   if (childCommand.head === "git") {
     const gitTokens = replacementToken === null ? [...childTokens, XARGS_APPENDED_INPUT] : childTokens;
-    const hasDynamicReplacement = replacementToken !== null && childTokens.some((token) => token.includes(replacementToken));
+    const hasDynamicReplacement = replacementToken !== null && (childTokens.some((token) => token.includes(replacementToken)) || Array.from(childCommand.envAssignments.values()).some((value) => value.includes(replacementToken)));
     const gitResult = analyzeGit(gitTokens, {
       cwd: childCommand.cwd,
       envAssignments: childCommand.envAssignments,

dist/index.js

@@ -3124,7 +3124,7 @@ function analyzeXargs(tokens, context) {
   }
   if (childCommand.head === "git") {
     const gitTokens = replacementToken === null ? [...childTokens, XARGS_APPENDED_INPUT] : childTokens;
-    const hasDynamicReplacement = replacementToken !== null && childTokens.some((token) => token.includes(replacementToken));
+    const hasDynamicReplacement = replacementToken !== null && (childTokens.some((token) => token.includes(replacementToken)) || Array.from(childCommand.envAssignments.values()).some((value) => value.includes(replacementToken)));
     const gitResult = analyzeGit(gitTokens, {
       cwd: childCommand.cwd,
       envAssignments: childCommand.envAssignments,

src/core/analyze/xargs.ts

@@ -66,7 +66,11 @@ export function analyzeXargs(
     const gitTokens =
       replacementToken === null ? [...childTokens, XARGS_APPENDED_INPUT] : childTokens;
     const hasDynamicReplacement =
-      replacementToken !== null && childTokens.some((token) => token.includes(replacementToken));
+      replacementToken !== null &&
+      (childTokens.some((token) => token.includes(replacementToken)) ||
+        Array.from(childCommand.envAssignments.values()).some((value) =>
+          value.includes(replacementToken),
+        ));
     const gitResult = analyzeGit(gitTokens, {
       cwd: childCommand.cwd,
       envAssignments: childCommand.envAssignments,

tests/core/rules-git.test.ts

@@ -1050,6 +1050,21 @@ describe('git linked worktree mode', () => {
     }
   });
 
+  test('SAFETY_NET_WORKTREE fails closed on dynamic xargs git env assignments', () => {
+    const fixture = createLinkedWorktreeFixture();
+    try {
+      withEnv({ SAFETY_NET_WORKTREE: '1' }, () => {
+        assertBlocked(
+          'echo ignored | xargs -I{} env EXTRA={} git reset --hard',
+          'git reset --hard',
+          fixture.linkedWorktree,
+        );
+      });
+    } finally {
+      fixture.cleanup();
+    }
+  });
+
   test('SAFETY_NET_WORKTREE fails closed on dynamic parallel git arguments', () => {
     const fixture = createLinkedWorktreeFixture();
     try {