Separate internal from non-internal unit tests of the C API

This helps us make sure that the external C API is sufficient for the
tasks that we think it is sufficient for.

src/libexpr-tests/meson.build

@@ -55,6 +55,7 @@ sources = files(
   'nix_api_expr.cc',
   'nix_api_external.cc',
   'nix_api_value.cc',
+  'nix_api_value_internal.cc',
   'primops.cc',
   'search-path.cc',
   'trivial.cc',

src/libexpr-tests/nix_api_expr.cc

@@ -1,7 +1,5 @@
 #include "nix_api_store.h"
-#include "nix_api_store_internal.h"
 #include "nix_api_util.h"
-#include "nix_api_util_internal.h"
 #include "nix_api_expr.h"
 #include "nix_api_value.h"
 
@@ -151,8 +149,8 @@ TEST_F(nix_api_expr_test, nix_expr_realise_context_bad_value)
     assert_ctx_ok();
     auto r = nix_string_realise(ctx, state, value, false);
     ASSERT_EQ(nullptr, r);
-    ASSERT_EQ(ctx->last_err_code, NIX_ERR_NIX_ERROR);
-    ASSERT_THAT(ctx->last_err, testing::Optional(testing::HasSubstr("cannot coerce")));
+    ASSERT_EQ(nix_err_code(ctx), NIX_ERR_NIX_ERROR);
+    ASSERT_THAT(nix_err_msg(nullptr, ctx, nullptr), testing::HasSubstr("cannot coerce"));
 }
 
 TEST_F(nix_api_expr_test, nix_expr_realise_context_bad_build)
@@ -168,8 +166,8 @@ TEST_F(nix_api_expr_test, nix_expr_realise_context_bad_build)
     assert_ctx_ok();
     auto r = nix_string_realise(ctx, state, value, false);
     ASSERT_EQ(nullptr, r);
-    ASSERT_EQ(ctx->last_err_code, NIX_ERR_NIX_ERROR);
-    ASSERT_THAT(ctx->last_err, testing::Optional(testing::HasSubstr("failed with exit code 1")));
+    ASSERT_EQ(nix_err_code(ctx), NIX_ERR_NIX_ERROR);
+    ASSERT_THAT(nix_err_msg(nullptr, ctx, nullptr), testing::HasSubstr("failed with exit code 1"));
 }
 
 TEST_F(nix_api_expr_test, nix_expr_realise_context)
@@ -381,12 +379,11 @@ TEST_F(nix_api_expr_test, nix_expr_primop_bad_no_return)
     nix_value * result = nix_alloc_value(ctx, state);
     assert_ctx_ok();
     nix_value_call(ctx, state, primopValue, three, result);
-    ASSERT_EQ(ctx->last_err_code, NIX_ERR_NIX_ERROR);
+    ASSERT_EQ(nix_err_code(ctx), NIX_ERR_NIX_ERROR);
     ASSERT_THAT(
-        ctx->last_err,
-        testing::Optional(
-            testing::HasSubstr("Implementation error in custom function: return value was not initialized")));
-    ASSERT_THAT(ctx->last_err, testing::Optional(testing::HasSubstr("badNoReturn")));
+        nix_err_msg(nullptr, ctx, nullptr),
+        testing::HasSubstr("Implementation error in custom function: return value was not initialized"));
+    ASSERT_THAT(nix_err_msg(nullptr, ctx, nullptr), testing::HasSubstr("badNoReturn"));
 }
 
 static void primop_bad_return_thunk(
@@ -419,12 +416,11 @@ TEST_F(nix_api_expr_test, nix_expr_primop_bad_return_thunk)
     assert_ctx_ok();
     NIX_VALUE_CALL(ctx, state, result, primopValue, toString, four);
 
-    ASSERT_EQ(ctx->last_err_code, NIX_ERR_NIX_ERROR);
+    ASSERT_EQ(nix_err_code(ctx), NIX_ERR_NIX_ERROR);
     ASSERT_THAT(
-        ctx->last_err,
-        testing::Optional(
-            testing::HasSubstr("Implementation error in custom function: return value must not be a thunk")));
-    ASSERT_THAT(ctx->last_err, testing::Optional(testing::HasSubstr("badReturnThunk")));
+        nix_err_msg(nullptr, ctx, nullptr),
+        testing::HasSubstr("Implementation error in custom function: return value must not be a thunk"));
+    ASSERT_THAT(nix_err_msg(nullptr, ctx, nullptr), testing::HasSubstr("badReturnThunk"));
 }
 
 TEST_F(nix_api_expr_test, nix_value_call_multi_no_args)

src/libexpr-tests/nix_api_external.cc

@@ -1,9 +1,6 @@
 #include "nix_api_store.h"
-#include "nix_api_store_internal.h"
 #include "nix_api_util.h"
-#include "nix_api_util_internal.h"
 #include "nix_api_expr.h"
-#include "nix_api_expr_internal.h"
 #include "nix_api_value.h"
 #include "nix_api_external.h"
 
@@ -39,7 +36,7 @@ private:
         std::string type_string = "nix-external<MyExternalValueDesc( ";
         type_string += std::to_string(obj->_x);
         type_string += " )>";
-        res->str = &*type_string.begin();
+        nix_set_string_return(res, &*type_string.begin());
     }
 };
 

src/libexpr-tests/nix_api_value.cc

@@ -1,10 +1,7 @@
 #include "nix_api_store.h"
-#include "nix_api_store_internal.h"
 #include "nix_api_util.h"
-#include "nix_api_util_internal.h"
 #include "nix_api_expr.h"
 #include "nix_api_value.h"
-#include "nix_api_expr_internal.h"
 
 #include "nix/expr/tests/nix_api_expr.hh"
 #include "nix/util/tests/string_callback.hh"
@@ -16,14 +13,6 @@
 
 namespace nixC {
 
-TEST_F(nix_api_expr_test, as_nix_value_ptr)
-{
-    // nix_alloc_value casts nix::Value to nix_value
-    // It should be obvious from the decl that that works, but if it doesn't,
-    // the whole implementation would be utterly broken.
-    ASSERT_EQ(sizeof(nix::Value), sizeof(nix_value));
-}
-
 TEST_F(nix_api_expr_test, nix_value_get_int_invalid)
 {
     ASSERT_EQ(0, nix_get_int(ctx, nullptr));
@@ -320,8 +309,10 @@ TEST_F(nix_api_expr_test, nix_value_init_apply_error)
 
     // Evaluate it
     nix_value_force(ctx, state, v);
-    ASSERT_EQ(ctx->last_err_code, NIX_ERR_NIX_ERROR);
-    ASSERT_THAT(ctx->last_err.value(), testing::HasSubstr("attempt to call something which is not a function but"));
+    ASSERT_EQ(nix_err_code(ctx), NIX_ERR_NIX_ERROR);
+    ASSERT_THAT(
+        nix_err_msg(nullptr, ctx, nullptr),
+        testing::HasSubstr("attempt to call something which is not a function but"));
 
     // Clean up
     nix_gc_decref(ctx, some_string);
@@ -380,7 +371,9 @@ TEST_F(nix_api_expr_test, nix_value_init_apply_lazy_arg)
     // nix_get_attr_byname isn't lazy (it could have been) so it will throw the exception
     nix_value * foo = nix_get_attr_byname(ctx, r, state, "foo");
     ASSERT_EQ(nullptr, foo);
-    ASSERT_THAT(ctx->last_err.value(), testing::HasSubstr("error message for test case nix_value_init_apply_lazy_arg"));
+    ASSERT_THAT(
+        nix_err_msg(nullptr, ctx, nullptr),
+        testing::HasSubstr("error message for test case nix_value_init_apply_lazy_arg"));
 
     // Clean up
     nix_gc_decref(ctx, f);

src/libexpr-tests/nix_api_value_internal.cc

@@ -0,0 +1,25 @@
+#include "nix_api_store.h"
+#include "nix_api_util.h"
+#include "nix_api_expr.h"
+#include "nix_api_value.h"
+#include "nix_api_expr_internal.h"
+
+#include "nix/expr/tests/nix_api_expr.hh"
+#include "nix/util/tests/string_callback.hh"
+
+#include <gmock/gmock.h>
+#include <cstddef>
+#include <cstdlib>
+#include <gtest/gtest.h>
+
+namespace nixC {
+
+TEST_F(nix_api_expr_test, as_nix_value_ptr)
+{
+    // nix_alloc_value casts nix::Value to nix_value
+    // It should be obvious from the decl that that works, but if it doesn't,
+    // the whole implementation would be utterly broken.
+    ASSERT_EQ(sizeof(nix::Value), sizeof(nix_value));
+}
+
+} // namespace nixC