WIP: add unit tests for libutil

This is a proof on concept to evaluate writing unit tests for Nix using
google test (https://github.com/google/googletest).

In order to execute tests:

$ make unit-tests
$ ./unit-tests

The Makefile rules for `unit-tests` is a complete hack.

4 files changed, 601 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index e3057c36c..06de35a27 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,8 @@ makefiles = \
   misc/upstart/local.mk \
   doc/manual/local.mk \
   tests/local.mk \
-  tests/plugins/local.mk
+  tests/plugins/local.mk \
+  tests/unit-tests/local.mk
 
 -include Makefile.config
 
diff --git a/release-common.nix b/release-common.nix
index b6c8f3d81..7e7de005d 100644
--- a/release-common.nix
+++ b/release-common.nix
@@ -55,6 +55,7 @@ rec {
       # Tests
       git
       mercurial
+      gmock
     ]
     ++ lib.optionals stdenv.isLinux [libseccomp utillinuxMinimal]
     ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
diff --git a/tests/unit-tests/local.mk b/tests/unit-tests/local.mk
new file mode 100644
index 000000000..ed11261c1
--- /dev/null
+++ b/tests/unit-tests/local.mk
@@ -0,0 +1,4 @@
+LIBS=-larchive -lcrypto -llzma -lbz2 -lz -lbrotlienc -lbrotlidec
+unit-tests:
+	echo $(nix_LDFLAGS)
+	$(CXX) -o unit-test $(nix_CXXFLAGS) $(nix_LDFLAGS) $(LIBS) --std=c++17 $$(pkg-config --libs gtest_main) ./src/libutil/*.o tests/unit-tests/test-util.cc
diff --git a/tests/unit-tests/test-util.cc b/tests/unit-tests/test-util.cc
new file mode 100644
index 000000000..05d8a0039
--- /dev/null
+++ b/tests/unit-tests/test-util.cc
@@ -0,0 +1,594 @@
+#include "../../src/libutil/util.hh"
+#include "../../src/libutil/types.hh"
+
+#include <gtest/gtest.h>
+
+namespace nix {
+
+    /* ----------------------------------------------------------------------------
+     * absPath
+     * --------------------------------------------------------------------------*/
+
+    TEST(absPath, doesntChangeRoot) {
+        auto p = absPath("/");
+
+        ASSERT_STREQ(p.c_str(), "/");
+    }
+
+    TEST(absPath, turnsEmptyPathIntoCWD) {
+        char cwd[PATH_MAX+1];
+        auto p = absPath("");
+
+        ASSERT_STREQ(p.c_str(), getcwd((char*)&cwd, PATH_MAX));
+    }
+
+    TEST(absPath, usesOptionalBasePathWhenGiven) {
+        char _cwd[PATH_MAX+1];
+        char* cwd = getcwd((char*)&_cwd, PATH_MAX);
+
+        auto p = absPath("", cwd);
+
+        ASSERT_STREQ(p.c_str(), cwd);
+    }
+
+    TEST(absPath, isIdempotent) {
+        char _cwd[PATH_MAX+1];
+        char* cwd = getcwd((char*)&_cwd, PATH_MAX);
+        auto p1 = absPath(cwd);
+        auto p2 = absPath(p1);
+
+        ASSERT_STREQ(p1.c_str(), p2.c_str());
+    }
+
+
+    TEST(absPath, pathIsCanonicalised) {
+        auto path = "/some/path/with/trailing/dot/.";
+        auto p1 = absPath(path);
+        auto p2 = absPath(p1);
+
+        ASSERT_STREQ(p1.c_str(), "/some/path/with/trailing/dot");
+        ASSERT_STREQ(p1.c_str(), p2.c_str());
+    }
+
+    /* ----------------------------------------------------------------------------
+     * canonPath
+     * --------------------------------------------------------------------------*/
+
+    TEST(canonPath, removesTrailingSlashes) {
+        auto path = "/this/is/a/path//";
+        auto p = canonPath(path);
+
+        ASSERT_STREQ(p.c_str(), "/this/is/a/path");
+    }
+
+    TEST(canonPath, removesDots) {
+        auto path = "/this/./is/a/path/./";
+        auto p = canonPath(path);
+
+        ASSERT_STREQ(p.c_str(), "/this/is/a/path");
+    }
+
+    TEST(canonPath, removesDots2) {
+        auto path = "/this/a/../is/a////path/foo/..";
+        auto p = canonPath(path);
+
+        ASSERT_STREQ(p.c_str(), "/this/is/a/path");
+    }
+
+    TEST(canonPath, requiresAbsolutePath) {
+        ASSERT_ANY_THROW(canonPath("."));
+        ASSERT_ANY_THROW(canonPath(".."));
+        ASSERT_ANY_THROW(canonPath("../"));
+        ASSERT_DEATH({ canonPath(""); }, "path != \"\"");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * dirOf
+     * --------------------------------------------------------------------------*/
+
+    // XXX: according to the doc of `dirOf`, dirOf("/") and dirOf("/foo")
+    // should both return "" but it actually returns "/" in both cases
+    TEST(dirOf, DISABLED_returnsEmptyStringForRoot) {
+        auto p = dirOf("/");
+
+        ASSERT_STREQ(p.c_str(), "");
+    }
+
+    TEST(dirOf, returnsFirstPathComponent) {
+        auto p1 = dirOf("/dir/");
+        ASSERT_STREQ(p1.c_str(), "/dir");
+        auto p2 = dirOf("/dir");
+        ASSERT_STREQ(p2.c_str(), "/");
+        auto p3 = dirOf("/dir/..");
+        ASSERT_STREQ(p3.c_str(), "/dir");
+        auto p4 = dirOf("/dir/../");
+        ASSERT_STREQ(p4.c_str(), "/dir/..");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * baseNameOf
+     * --------------------------------------------------------------------------*/
+
+    TEST(baseNameOf, emptyPath) {
+        auto p1 = baseNameOf("");
+        ASSERT_STREQ(std::string(p1).c_str(), "");
+    }
+
+    TEST(baseNameOf, pathOnRoot) {
+        auto p1 = baseNameOf("/dir");
+        ASSERT_STREQ(std::string(p1).c_str(), "dir");
+    }
+
+    TEST(baseNameOf, relativePath) {
+        auto p1 = baseNameOf("dir/foo");
+        ASSERT_STREQ(std::string(p1).c_str(), "foo");
+    }
+
+    TEST(baseNameOf, pathWithTrailingSlashRoot) {
+        auto p1 = baseNameOf("/");
+        ASSERT_STREQ(std::string(p1).c_str(), "");
+    }
+
+    // XXX: according to the doc of `baseNameOf`, baseNameOf("/dir/") should return
+    // "" but it actually returns "dir"
+    TEST(baseNameOf, DISABLED_trailingSlash) {
+        auto p1 = baseNameOf("/dir/");
+        ASSERT_STREQ(std::string(p1).c_str(), "");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * isInDir
+     * --------------------------------------------------------------------------*/
+
+    TEST(isInDir, trivialCase) {
+        auto p1 = isInDir("/foo/bar", "/foo");
+        ASSERT_EQ(p1, true);
+    }
+
+    TEST(isInDir, notInDir) {
+        auto p1 = isInDir("/zes/foo/bar", "/foo");
+        ASSERT_EQ(p1, false);
+    }
+
+    // XXX: hm, bug or feature? :) Looking at the implementation
+    // this might be problematic.
+    TEST(isInDir, emptyDir) {
+        auto p1 = isInDir("/zes/foo/bar", "");
+        ASSERT_EQ(p1, true);
+    }
+
+    /* ----------------------------------------------------------------------------
+     * isDirOrInDir
+     * --------------------------------------------------------------------------*/
+
+    TEST(isDirOrInDir, trueForSameDirectory) {
+        ASSERT_EQ(isDirOrInDir("/nix", "/nix"), true);
+        ASSERT_EQ(isDirOrInDir("/", "/"), true);
+    }
+
+    TEST(isDirOrInDir, trueForEmptyPaths) {
+        ASSERT_EQ(isDirOrInDir("", ""), true);
+    }
+
+    TEST(isDirOrInDir, falseForDisjunctPaths) {
+        ASSERT_EQ(isDirOrInDir("/foo", "/bar"), false);
+    }
+
+    TEST(isDirOrInDir, relativePaths) {
+        ASSERT_EQ(isDirOrInDir("/foo/..", "/foo"), true);
+    }
+
+    // XXX: while it is possible to use "." or ".." in the
+    // first argument this doesn't seem to work in the second.
+    TEST(isDirOrInDir, DISABLED_shouldWork) {
+        ASSERT_EQ(isDirOrInDir("/foo/..", "/foo/."), true);
+
+    }
+
+    /* ----------------------------------------------------------------------------
+     * pathExists
+     * --------------------------------------------------------------------------*/
+
+    TEST(pathExists, rootExists) {
+        ASSERT_TRUE(pathExists("/"));
+    }
+
+    TEST(pathExists, cwdExists) {
+        ASSERT_TRUE(pathExists("."));
+    }
+
+    TEST(pathExists, bogusPathDoesNotExist) {
+        ASSERT_FALSE(pathExists("/home/schnitzel/darmstadt/pommes"));
+    }
+
+    /* ----------------------------------------------------------------------------
+     * concatStringsSep
+     * --------------------------------------------------------------------------*/
+
+    TEST(concatStringsSep, buildCommaSeparatedString) {
+        Strings strings;
+        strings.push_back("this");
+        strings.push_back("is");
+        strings.push_back("great");
+
+        ASSERT_EQ(concatStringsSep(",", strings), "this,is,great");
+    }
+
+    TEST(concatStringsSep, buildStringWithEmptySeparator) {
+        Strings strings;
+        strings.push_back("this");
+        strings.push_back("is");
+        strings.push_back("great");
+
+        ASSERT_EQ(concatStringsSep("", strings), "thisisgreat");
+    }
+
+    TEST(concatStringsSep, buildSingleString) {
+        Strings strings;
+        strings.push_back("this");
+
+        ASSERT_EQ(concatStringsSep(",", strings), "this");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * hasPrefix
+     * --------------------------------------------------------------------------*/
+
+    TEST(hasPrefix, emptyStringHasNoPrefix) {
+        ASSERT_FALSE(hasPrefix("", "foo"));
+    }
+
+    TEST(hasPrefix, emptyStringIsAlwaysPrefix) {
+        ASSERT_TRUE(hasPrefix("foo", ""));
+        ASSERT_TRUE(hasPrefix("jshjkfhsadf", ""));
+    }
+
+    TEST(hasPrefix, trivialCase) {
+        ASSERT_TRUE(hasPrefix("foobar", "foo"));
+    }
+
+    /* ----------------------------------------------------------------------------
+     * hasSuffix
+     * --------------------------------------------------------------------------*/
+
+    TEST(hasSuffix, emptyStringHasNoSuffix) {
+        ASSERT_FALSE(hasSuffix("", "foo"));
+    }
+
+    TEST(hasSuffix, trivialCase) {
+        ASSERT_TRUE(hasSuffix("foo", "foo"));
+        ASSERT_TRUE(hasSuffix("foobar", "bar"));
+    }
+
+    /* ----------------------------------------------------------------------------
+     * base64Encode
+     * --------------------------------------------------------------------------*/
+
+    TEST(base64Encode, emptyString) {
+        ASSERT_STREQ(base64Encode("").c_str(), "");
+    }
+
+    TEST(base64Encode, encodesAString) {
+        ASSERT_STREQ(base64Encode("quod erat demonstrandum").c_str(), "cXVvZCBlcmF0IGRlbW9uc3RyYW5kdW0=");
+    }
+
+    TEST(base64Encode, encodeAndDecode) {
+        auto s = "quod erat demonstrandum";
+        auto encoded = base64Encode(s);
+        auto decoded = base64Decode(encoded);
+
+        ASSERT_STREQ(decoded.c_str(), s);
+    }
+
+    /* ----------------------------------------------------------------------------
+     * base64Decode
+     * --------------------------------------------------------------------------*/
+
+    TEST(base64Decode, emptyString) {
+        ASSERT_STREQ(base64Decode("").c_str(), "");
+    }
+
+    TEST(base64Decode, decodeAString) {
+        ASSERT_STREQ(base64Decode("cXVvZCBlcmF0IGRlbW9uc3RyYW5kdW0=").c_str(), "quod erat demonstrandum");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * toLower
+     * --------------------------------------------------------------------------*/
+
+    TEST(toLower, emptyString) {
+        ASSERT_STREQ(toLower("").c_str(), "");
+    }
+
+    TEST(toLower, nonLetters) {
+        auto s = "!@(*$#)(@#=\\234_";
+        ASSERT_STREQ(toLower(s).c_str(), s);
+    }
+
+    // XXX: std::tolower() doesn't cover this. This probably doesn't matter
+    // since the context is paths and store paths specifically where such
+    // characters are not allowed.
+    TEST(toLower, DISABLED_umlauts) {
+        auto s = "ÄÖÜ";
+        ASSERT_STREQ(toLower(s).c_str(), "äöü");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * string2Float
+     * --------------------------------------------------------------------------*/
+
+    TEST(string2Float, emptyString) {
+        double n;
+        ASSERT_EQ(string2Float("", n), false);
+    }
+
+    TEST(string2Float, trivialConversions) {
+        double n;
+        ASSERT_EQ(string2Float("1.0", n), true);
+        ASSERT_EQ(n, 1.0);
+
+        ASSERT_EQ(string2Float("0.0", n), true);
+        ASSERT_EQ(n, 0.0);
+
+        ASSERT_EQ(string2Float("-100.25", n), true);
+        ASSERT_EQ(n, (-100.25));
+    }
+
+    /* ----------------------------------------------------------------------------
+     * string2Int
+     * --------------------------------------------------------------------------*/
+
+    TEST(string2Int, emptyString) {
+        double n;
+        ASSERT_EQ(string2Int("", n), false);
+    }
+
+    TEST(string2Int, trivialConversions) {
+        double n;
+        ASSERT_EQ(string2Int("1", n), true);
+        ASSERT_EQ(n, 1);
+
+        ASSERT_EQ(string2Int("0", n), true);
+        ASSERT_EQ(n, 0);
+
+        ASSERT_EQ(string2Int("-100", n), true);
+        ASSERT_EQ(n, (-100));
+    }
+
+    /* ----------------------------------------------------------------------------
+     * statusOk
+     * --------------------------------------------------------------------------*/
+
+    TEST(statusOk, zeroIsOk) {
+        ASSERT_EQ(statusOk(0), true);
+        ASSERT_EQ(statusOk(1), false);
+    }
+
+    /* ----------------------------------------------------------------------------
+     * replaceInSet : XXX: this function isn't called anywhere!
+     * --------------------------------------------------------------------------*/
+
+
+    /* ----------------------------------------------------------------------------
+     * rewriteStrings
+     * --------------------------------------------------------------------------*/
+
+    TEST(rewriteStrings, emptyString) {
+        StringMap rewrites;
+        rewrites["this"] = "that";
+
+        ASSERT_STREQ(rewriteStrings("", rewrites).c_str(), "");
+    }
+
+    TEST(rewriteStrings, emptyRewrites) {
+        StringMap rewrites;
+
+        ASSERT_STREQ(rewriteStrings("this and that", rewrites).c_str(), "this and that");
+    }
+
+    TEST(rewriteStrings, successfulRewrite) {
+        StringMap rewrites;
+        rewrites["this"] = "that";
+
+        ASSERT_STREQ(rewriteStrings("this and that", rewrites).c_str(), "that and that");
+    }
+
+    TEST(rewriteStrings, doesntOccur) {
+        StringMap rewrites;
+        rewrites["foo"] = "bar";
+
+        ASSERT_STREQ(rewriteStrings("this and that", rewrites).c_str(), "this and that");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * replaceStrings
+     * --------------------------------------------------------------------------*/
+
+    TEST(replaceStrings, emptyString) {
+        ASSERT_STREQ(replaceStrings("", "this", "that").c_str(), "");
+        ASSERT_STREQ(replaceStrings("this and that", "", "").c_str(), "this and that");
+    }
+
+    TEST(replaceStrings, successfulReplace) {
+        ASSERT_STREQ(replaceStrings("this and that", "this", "that").c_str(), "that and that");
+    }
+
+    TEST(replaceStrings, doesntOccur) {
+        ASSERT_STREQ(replaceStrings("this and that", "foo", "bar").c_str(), "this and that");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * trim
+     * --------------------------------------------------------------------------*/
+
+    TEST(trim, emptyString) {
+        ASSERT_STREQ(trim("").c_str(), "");
+    }
+
+    TEST(trim, removesWhitespace) {
+        ASSERT_STREQ(trim("foo").c_str(), "foo");
+        ASSERT_STREQ(trim("     foo ").c_str(), "foo");
+        ASSERT_STREQ(trim("     foo bar baz").c_str(), "foo bar baz");
+        ASSERT_STREQ(trim("     \t foo bar baz\n").c_str(), "foo bar baz");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * chomp
+     * --------------------------------------------------------------------------*/
+
+    TEST(chomp, emptyString) {
+        ASSERT_STREQ(chomp("").c_str(), "");
+    }
+
+    TEST(chomp, removesWhitespace) {
+        ASSERT_STREQ(chomp("foo").c_str(), "foo");
+        ASSERT_STREQ(chomp("foo ").c_str(), "foo");
+        ASSERT_STREQ(chomp(" foo ").c_str(), " foo");
+        ASSERT_STREQ(chomp(" foo bar baz  ").c_str(), " foo bar baz");
+        ASSERT_STREQ(chomp("\t foo bar baz\n").c_str(), "\t foo bar baz");
+    }
+
+    /* ----------------------------------------------------------------------------
+     * quoteStrings
+     * --------------------------------------------------------------------------*/
+
+    TEST(quoteStrings, empty) {
+        Strings s = { };
+        Strings expected = { };
+
+        ASSERT_EQ(quoteStrings(s), expected);
+    }
+
+    TEST(quoteStrings, emptyStrings) {
+        Strings s = { "", "", "" };
+        Strings expected = { "''", "''", "''" };
+        ASSERT_EQ(quoteStrings(s), expected);
+
+    }
+
+    TEST(quoteStrings, trivialQuote) {
+        Strings s = { "foo", "bar", "baz" };
+        Strings expected = { "'foo'", "'bar'", "'baz'" };
+
+        ASSERT_EQ(quoteStrings(s), expected);
+    }
+
+    TEST(quoteStrings, quotedStrings) {
+        Strings s = { "'foo'", "'bar'", "'baz'" };
+        Strings expected = { "''foo''", "''bar''", "''baz''" };
+
+        ASSERT_EQ(quoteStrings(s), expected);
+    }
+
+    /* ----------------------------------------------------------------------------
+     * tokenizeString
+     * --------------------------------------------------------------------------*/
+
+    TEST(tokenizeString, empty) {
+        auto s = "";
+        Strings expected = {  };
+
+        ASSERT_EQ(tokenizeString<Strings>(""), expected);
+    }
+
+    TEST(tokenizeString, tokenizeSpacesWithDefaults) {
+        auto s = "foo bar baz";
+        Strings expected = { "foo", "bar", "baz" };
+
+        ASSERT_EQ(tokenizeString<Strings>(s), expected);
+    }
+
+    TEST(tokenizeString, tokenizeTabsWithDefaults) {
+        auto s = "foo\tbar\tbaz";
+        Strings expected = { "foo", "bar", "baz" };
+
+        ASSERT_EQ(tokenizeString<Strings>(s), expected);
+    }
+
+    TEST(tokenizeString, tokenizeTabsSpacesWithDefaults) {
+        auto s = "foo\t bar\t baz";
+        Strings expected = { "foo", "bar", "baz" };
+
+        ASSERT_EQ(tokenizeString<Strings>(s), expected);
+    }
+
+    TEST(tokenizeString, tokenizeTabsSpacesNewlineWithDefaults) {
+        auto s = "foo\t\n bar\t\n baz";
+        Strings expected = { "foo", "bar", "baz" };
+
+        ASSERT_EQ(tokenizeString<Strings>(s), expected);
+    }
+
+    TEST(tokenizeString, tokenizeTabsSpacesNewlineRetWithDefaults) {
+        auto s = "foo\t\n\r bar\t\n\r baz";
+        Strings expected = { "foo", "bar", "baz" };
+
+        ASSERT_EQ(tokenizeString<Strings>(s), expected);
+
+        auto s2 = "foo \t\n\r bar \t\n\r baz";
+        Strings expected2 = { "foo", "bar", "baz" };
+
+        ASSERT_EQ(tokenizeString<Strings>(s2), expected2);
+    }
+
+    TEST(tokenizeString, tokenizeWithCustomSep) {
+        auto s = "foo\n,bar\n,baz\n";
+        Strings expected = { "foo\n", "bar\n", "baz\n" };
+
+        ASSERT_EQ(tokenizeString<Strings>(s, ","), expected);
+    }
+
+    /* ----------------------------------------------------------------------------
+     * get
+     * --------------------------------------------------------------------------*/
+
+    TEST(get, emptyContainer) {
+        StringMap s = { };
+        auto expected = std::nullopt;
+
+        ASSERT_EQ(get(s, "one"), expected);
+    }
+
+    TEST(get, getFromContainer) {
+        StringMap s;
+        s["one"] = "yi";
+        s["two"] = "er";
+        auto expected = "yi";
+
+        ASSERT_EQ(get(s, "one"), expected);
+    }
+
+    /* ----------------------------------------------------------------------------
+     * filterANSIEscapes
+     * --------------------------------------------------------------------------*/
+
+    TEST(filterANSIEscapes, emptyString) {
+        auto s = "";
+        auto expected = "";
+
+        ASSERT_STREQ(filterANSIEscapes(s).c_str(), expected);
+    }
+
+    TEST(filterANSIEscapes, doesntChangePrintableChars) {
+        auto s = "09 2q304ruyhr slk2-19024 kjsadh sar f";
+
+        ASSERT_STREQ(filterANSIEscapes(s).c_str(), s);
+    }
+
+    TEST(filterANSIEscapes, filtersColorCodes) {
+        auto s = "\u001b[30m A \u001b[31m B \u001b[32m C \u001b[33m D \u001b[0m";
+
+        ASSERT_STREQ(filterANSIEscapes(s, true, 2).c_str(), " A" );
+        ASSERT_STREQ(filterANSIEscapes(s, true, 3).c_str(), " A " );
+        ASSERT_STREQ(filterANSIEscapes(s, true, 4).c_str(), " A  " );
+        ASSERT_STREQ(filterANSIEscapes(s, true, 5).c_str(), " A  B" );
+        ASSERT_STREQ(filterANSIEscapes(s, true, 8).c_str(), " A  B  C" );
+    }
+
+    TEST(filterANSIEscapes, expandsTabs) {
+        auto s = "foo\tbar\tbaz";
+
+        ASSERT_STREQ(filterANSIEscapes(s, true).c_str(), "foo     bar     baz" );
+    }
+
+}