diff --git a/test/common.js b/test/common.js
index 2bb4a76..bc2c4da 100644
--- a/test/common.js
+++ b/test/common.js
@@ -6,6 +6,11 @@ import utils from './utils/utils';
 
 shell.config.silent = true;
 
+test.beforeEach(() => {
+  common.state.error = null;
+  common.state.errorCode = 0;
+});
+
 //
 // Invalids
 //
@@ -22,6 +27,26 @@ test('should be a list', t => {
   }, TypeError);
 });
 
+test('parseOptions (invalid option in options object)', t => {
+  t.throws(() => {
+    common.parseOptions({ q: 'some string value' }, {
+      R: 'recursive',
+      f: 'force',
+      r: 'reverse',
+    });
+  });
+});
+
+test('parseOptions (invalid type)', t => {
+  t.throws(() => {
+    common.parseOptions(12, {
+      R: 'recursive',
+      f: 'force',
+      r: 'reverse',
+    });
+  });
+});
+
 //
 // Valids
 //
diff --git a/test/cp.js b/test/cp.js
index 4cb16e5..74c8dd8 100644
--- a/test/cp.js
+++ b/test/cp.js
@@ -71,7 +71,7 @@ test('source does not exist', t => {
   t.is(result.stderr, 'cp: no such file or directory: asdfasdf');
 });
 
-test('sources does not exist', t => {
+test('multiple sources do not exist', t => {
   const result = shell.cp('asdfasdf1', 'asdfasdf2', t.context.tmp);
   t.truthy(shell.error());
   t.is(result.code, 1);
@@ -112,6 +112,32 @@ test('dest already exists', t => {
   t.is(shell.cat('resources/file2').toString(), oldContents);
 });
 
+test('-nR does not overwrite an existing file at the destination', t => {
+  // Create tmp/new/cp/a
+  const dest = `${t.context.tmp}/new/cp`;
+  shell.mkdir('-p', dest);
+  const oldContents = 'original content';
+  shell.ShellString(oldContents).to(`${dest}/a`);
+
+  // Attempt to overwrite /tmp/new/cp/ with resources/cp/
+  const result = shell.cp('-nR', 'resources/cp/', `${t.context.tmp}/new/`);
+  t.falsy(shell.error());
+  t.is(result.code, 0);
+  t.falsy(result.stderr);
+  t.is(shell.cat(`${dest}/a`).toString(), oldContents);
+});
+
+test('-n does not overwrite an existing file if the destination is a directory', t => {
+  const oldContents = 'original content';
+  shell.cp('resources/file1', `${t.context.tmp}`);
+  new common.ShellString(oldContents).to(`${t.context.tmp}/file1`);
+  const result = shell.cp('-n', 'resources/file1', `${t.context.tmp}`);
+  t.falsy(shell.error());
+  t.is(result.code, 0);
+  t.falsy(result.stderr);
+  t.is(shell.cat(`${t.context.tmp}/file1`).toString(), oldContents);
+});
+
 test('-f by default', t => {
   shell.cp('resources/file2', 'resources/copyfile2');
   const result = shell.cp('resources/file1', 'resources/file2'); // dest already exists
@@ -215,6 +241,15 @@ test('recursive, with regular files', t => {
   t.truthy(fs.existsSync(`${t.context.tmp}/file2`));
 });
 
+test('omit directory if missing recursive flag', t => {
+  const result = shell.cp('resources/cp', t.context.tmp);
+  t.is(shell.error(), "cp: omitting directory 'resources/cp'");
+  t.is(result.stderr, "cp: omitting directory 'resources/cp'");
+  t.is(result.code, 1);
+  t.falsy(fs.existsSync(`${t.context.tmp}/file1`));
+  t.falsy(fs.existsSync(`${t.context.tmp}/file2`));
+});
+
 test('recursive, nothing exists', t => {
   const result = shell.cp('-R', 'resources/cp', t.context.tmp);
   t.falsy(shell.error());
diff --git a/test/mv.js b/test/mv.js
index dcf1e22..9d3fbaf 100644
--- a/test/mv.js
+++ b/test/mv.js
@@ -91,6 +91,15 @@ test('-n is no-force/no-clobber', t => {
   t.is(result.stderr, 'mv: dest file already exists: file2');
 });
 
+test('-n option with a directory as the destination', t => {
+  shell.cp('file1', 'cp'); // copy it so we're sure it's already there
+  const result = shell.mv('-n', 'file1', 'cp');
+  t.truthy(shell.error());
+  t.is(result.code, 1);
+  // TODO(nate): make this an equals comparison once issue #681 is resolved
+  t.regex(result.stderr, /mv: dest file already exists: cp.file1/);
+});
+
 test('-f is the default behavior', t => {
   const result = shell.mv('file1', 'file2'); // dest already exists (but that's ok)
   t.falsy(shell.error());
@@ -153,19 +162,13 @@ test('one source', t => {
 });
 
 test('two sources', t => {
-  shell.rm('-rf', 't');
-  shell.mkdir('-p', 't');
-  let result = shell.mv('file1', 'file2', 't');
+  const result = shell.mv('file1', 'file2', 'cp');
   t.falsy(shell.error());
   t.is(result.code, 0);
   t.falsy(fs.existsSync('file1'));
   t.falsy(fs.existsSync('file2'));
-  t.truthy(fs.existsSync('t/file1'));
-  t.truthy(fs.existsSync('t/file2'));
-  result = shell.mv('t/*', '.'); // revert
-  t.is(result.code, 0);
-  t.truthy(fs.existsSync('file1'));
-  t.truthy(fs.existsSync('file2'));
+  t.truthy(fs.existsSync('cp/file1'));
+  t.truthy(fs.existsSync('cp/file2'));
 });
 
 test('two sources, array style', t => {
diff --git a/test/rm.js b/test/rm.js
index cdb3e92..1d88a88 100644
--- a/test/rm.js
+++ b/test/rm.js
@@ -35,6 +35,13 @@ test('file does not exist', t => {
   t.is(result.stderr, 'rm: no such file or directory: asdfasdf');
 });
 
+test('cannot delete a directoy without recursive flag', t => {
+  const result = shell.rm(`${t.context.tmp}/rm`);
+  t.truthy(shell.error());
+  t.is(result.code, 1);
+  t.is(result.stderr, 'rm: path is a directory');
+});
+
 test('only an option', t => {
   const result = shell.rm('-f');
   t.truthy(shell.error());
diff --git a/test/toEnd.js b/test/toEnd.js
index 323e4a8..cdb7fb6 100644
--- a/test/toEnd.js
+++ b/test/toEnd.js
@@ -30,6 +30,12 @@ test('missing file argument', t => {
   t.truthy(shell.error());
 });
 
+test('cannot write to a non-existent directory', t => {
+  t.falsy(fs.existsSync('/asdfasdf')); // sanity check
+  shell.ShellString('hello world').toEnd('/asdfasdf/file');
+  t.truthy(shell.error());
+});
+
 //
 // Valids
 //