Rewrite REPL test parser

- Use a recursive descent parser so that it's easy to extend.
- Add `@args` to enable customizing command-line arguments
- Add `@should-start` to enable `nix repl` tests that error before
  entering the REPL
- Make sure to read all stdout output before comparing. This catches
  some extra output we were tossing out before!

Change-Id: I5522555df4c313024ab15cd10f9f04e7293bda3a

1 files changed, 111 insertions, 53 deletions

diff --git a/tests/functional/repl_characterization/repl_characterization.cc b/tests/functional/repl_characterization/repl_characterization.cc
index 68a66b2f3..fa5a7ba74 100644
--- a/tests/functional/repl_characterization/repl_characterization.cc
+++ b/tests/functional/repl_characterization/repl_characterization.cc
@@ -1,16 +1,17 @@
 #include <gtest/gtest.h>
 
+#include <boost/algorithm/string/replace.hpp>
+#include <optional>
 #include <string>
 #include <string_view>
-#include <optional>
 #include <unistd.h>
-#include <boost/algorithm/string/replace.hpp>
 
+#include "escape-string.hh"
 #include "test-session.hh"
-#include "util.hh"
 #include "tests/characterization.hh"
 #include "tests/cli-literate-parser.hh"
 #include "tests/terminal-code-eater.hh"
+#include "util.hh"
 
 using namespace std::string_literals;
 
@@ -40,92 +41,149 @@ public:
         return unitTestData + "/" + testStem;
     }
 
-    void runReplTest(std::string_view const & content, std::vector<std::string> extraArgs = {}) const
+    void runReplTest(const std::string content, std::vector<std::string> extraArgs = {}) const
     {
-        auto syntax = CLILiterateParser::parse(std::string(REPL_PROMPT), content);
+        auto parsed = cli_literate_parser::parse(
+            content, cli_literate_parser::Config{.prompt = std::string(REPL_PROMPT), .indent = 2}
+        );
+        parsed.interpolatePwd(unitTestData);
 
         // FIXME: why does this need two --quiets
-        // show-trace is on by default due to test configuration, but is not a standard
-        Strings args{"--quiet", "repl", "--quiet", "--option", "show-trace", "false", "--offline", "--extra-experimental-features", "repl-automation"};
+        // show-trace is on by default due to test configuration, but is not a
+        // standard
+        Strings args{
+            "--quiet",
+            "repl",
+            "--quiet",
+            "--option",
+            "show-trace",
+            "false",
+            "--offline",
+            "--extra-experimental-features",
+            "repl-automation",
+        };
         args.insert(args.end(), extraArgs.begin(), extraArgs.end());
+        args.insert(args.end(), parsed.args.begin(), parsed.args.end());
 
         auto nixBin = canonPath(getEnvNonEmpty("NIX_BIN_DIR").value_or(NIX_BIN_DIR));
 
         auto process = RunningProcess::start(nixBin + "/nix", args);
-        auto session = TestSession{std::string(AUTOMATION_PROMPT), std::move(process)};
-
-        for (auto & bit : syntax) {
-            if (bit.kind != CLILiterateParser::NodeKind::COMMAND) {
-                continue;
-            }
-
-            if (!session.waitForPrompt()) {
-                ASSERT_TRUE(false);
-            }
-            session.runCommand(bit.text);
+        auto session = TestSession(std::string(AUTOMATION_PROMPT), std::move(process));
+
+        for (auto & event : parsed.syntax) {
+            std::visit(
+                overloaded{
+                    [&](const cli_literate_parser::Command & e) {
+                        ASSERT_TRUE(session.waitForPrompt());
+                        if (e.text == ":quit") {
+                            // If we quit the repl explicitly, we won't have a
+                            // prompt when we're done.
+                            parsed.shouldStart = false;
+                        }
+                        session.runCommand(e.text);
+                    },
+                    [&](const auto & e) {},
+                },
+                event
+            );
         }
-        if (!session.waitForPrompt()) {
-            ASSERT_TRUE(false);
+        if (parsed.shouldStart) {
+            ASSERT_TRUE(session.waitForPrompt());
         }
         session.close();
 
-        auto replacedOutLog = boost::algorithm::replace_all_copy(session.outLog, unitTestData, "TEST_DATA");
+        auto replacedOutLog =
+            boost::algorithm::replace_all_copy(session.outLog, unitTestData, "$TEST_DATA");
         auto cleanedOutLog = trimOutLog(replacedOutLog);
 
-        auto parsedOutLog = CLILiterateParser::parse(std::string(AUTOMATION_PROMPT), cleanedOutLog, 0);
+        auto parsedOutLog = cli_literate_parser::parse(
+            std::string(cleanedOutLog),
+            cli_literate_parser::Config{.prompt = std::string(AUTOMATION_PROMPT), .indent = 0}
+        );
 
-        parsedOutLog = CLILiterateParser::tidyOutputForComparison(std::move(parsedOutLog));
-        syntax = CLILiterateParser::tidyOutputForComparison(std::move(syntax));
+        auto expected = parsed.tidyOutputForComparison();
+        auto actual = parsedOutLog.tidyOutputForComparison();
 
-        ASSERT_EQ(parsedOutLog, syntax);
+        ASSERT_EQ(expected, actual);
+    }
+
+    void runReplTestPath(const std::string_view & nameBase, std::vector<std::string> extraArgs)
+    {
+        auto nixPath = goldenMaster(nameBase + ".nix");
+        if (pathExists(nixPath)) {
+            extraArgs.push_back("-f");
+            extraArgs.push_back(nixPath);
+        }
+        readTest(nameBase + ".test", [this, extraArgs](std::string input) {
+            runReplTest(input, extraArgs);
+        });
+    }
+
+    void runReplTestPath(const std::string_view & nameBase)
+    {
+        runReplTestPath(nameBase, {});
+    }
+
+    void runDebuggerTest(const std::string_view & nameBase)
+    {
+        runReplTestPath(nameBase, {"--debugger"});
     }
 };
 
-TEST_F(ReplSessionTest, parses)
+TEST_F(ReplSessionTest, round_trip)
 {
-    writeTest("basic.ast", [this]() {
+    writeTest("basic.test", [this]() {
         const std::string content = readFile(goldenMaster("basic.test"));
-        auto parser = CLILiterateParser{std::string(REPL_PROMPT)};
-        parser.feed(content);
+        auto parsed = cli_literate_parser::parse(
+            content, cli_literate_parser::Config{.prompt = std::string(REPL_PROMPT)}
+        );
 
         std::ostringstream out{};
-        for (auto & bit : parser.syntax()) {
-            out << bit.print() << "\n";
+        for (auto & node : parsed.syntax) {
+            cli_literate_parser::unparseNode(out, node, true);
         }
         return out.str();
     });
+}
 
+TEST_F(ReplSessionTest, tidy)
+{
+    writeTest("basic.ast", [this]() {
+        const std::string content = readFile(goldenMaster("basic.test"));
+        auto parsed = cli_literate_parser::parse(
+            content, cli_literate_parser::Config{.prompt = std::string(REPL_PROMPT)}
+        );
+        std::ostringstream out{};
+        for (auto & node : parsed.syntax) {
+            out << debugNode(node) << "\n";
+        }
+        return out.str();
+    });
     writeTest("basic_tidied.ast", [this]() {
         const std::string content = readFile(goldenMaster("basic.test"));
-        auto syntax = CLILiterateParser::parse(std::string(REPL_PROMPT), content);
-
-        syntax = CLILiterateParser::tidyOutputForComparison(std::move(syntax));
-
+        auto parsed = cli_literate_parser::parse(
+            content, cli_literate_parser::Config{.prompt = std::string(REPL_PROMPT)}
+        );
+        auto tidied = parsed.tidyOutputForComparison();
         std::ostringstream out{};
-        for (auto & bit : syntax) {
-            out << bit.print() << "\n";
+        for (auto & node : tidied) {
+            out << debugNode(node) << "\n";
         }
         return out.str();
     });
 }
 
-TEST_F(ReplSessionTest, repl_basic)
-{
-    readTest("basic_repl.test", [this](std::string input) { runReplTest(input); });
-}
-
-#define DEBUGGER_TEST(name) \
+#define REPL_TEST(name)           \
     TEST_F(ReplSessionTest, name) \
-    { \
-        readTest(#name ".test", [this](std::string input) { \
-            runReplTest(input, {"--debugger", "-f", goldenMaster(#name ".nix")}); \
-        }); \
+    {                             \
+        runReplTestPath(#name);   \
     }
 
-DEBUGGER_TEST(regression_9918);
-DEBUGGER_TEST(regression_9917);
-DEBUGGER_TEST(regression_l145);
-DEBUGGER_TEST(stack_vars);
-DEBUGGER_TEST(no_nested_debuggers);
+REPL_TEST(basic_repl);
+REPL_TEST(no_nested_debuggers);
+REPL_TEST(regression_9917);
+REPL_TEST(regression_9918);
+REPL_TEST(regression_l145);
+REPL_TEST(stack_vars);
 
-};
+}; // namespace nix