Make nodes opaque

6 files changed, 195 insertions, 189 deletions

diff --git a/test/headers/test_headers.c b/test/headers/test_headers.c
index c855c103..62be0976 100644
--- a/test/headers/test_headers.c
+++ b/test/headers/test_headers.c
@@ -3,8 +3,7 @@
 
 #include "serd/serd.h" // IWYU pragma: keep
 
-SERD_CONST_FUNC
-int
+SERD_CONST_FUNC int
 main(void)
 {
   return 0;
diff --git a/test/test_env.c b/test/test_env.c
index 8ef95f1a..198c7e9b 100644
--- a/test/test_env.c
+++ b/test/test_env.c
@@ -24,64 +24,68 @@ count_prefixes(void* handle, const SerdNode* name, const SerdNode* uri)
 static void
 test_env(void)
 {
-  SerdNode u   = serd_node_from_string(SERD_URI, "http://example.org/foo");
-  SerdNode b   = serd_node_from_string(SERD_CURIE, "invalid");
-  SerdNode c   = serd_node_from_string(SERD_CURIE, "eg.2:b");
-  SerdEnv* env = serd_env_new(NULL);
+  SerdNode* u   = serd_new_string(SERD_URI, "http://example.org/foo");
+  SerdNode* b   = serd_new_string(SERD_CURIE, "invalid");
+  SerdNode* c   = serd_new_string(SERD_CURIE, "eg.2:b");
+  SerdNode* s   = serd_new_string(SERD_LITERAL, "hello");
+  SerdEnv*  env = serd_env_new(NULL);
   serd_env_set_prefix_from_strings(env, "eg.2", "http://example.org/");
 
-  assert(!serd_env_set_base_uri(env, NULL));
-  assert(serd_env_set_base_uri(env, &SERD_NODE_NULL));
-  assert(serd_node_equals(serd_env_base_uri(env, NULL), &SERD_NODE_NULL));
+  assert(!serd_env_new(s));
 
-  SerdStringView prefix;
-  SerdStringView suffix;
-  assert(!serd_env_qualify(NULL, &u, &u, &suffix));
-  assert(serd_env_expand(NULL, &c, &prefix, &suffix));
-  assert(serd_env_expand(env, &b, &prefix, &suffix));
+  const SerdNode* prefix_node = NULL;
+  SerdStringView  prefix      = serd_empty_string();
+  SerdStringView  suffix      = serd_empty_string();
 
-  SerdNode nxnode = serd_env_expand_node(NULL, &c);
-  assert(serd_node_equals(&nxnode, &SERD_NODE_NULL));
+  assert(!serd_env_qualify(NULL, u, &prefix_node, &suffix));
 
-  SerdNode xnode = serd_env_expand_node(env, &SERD_NODE_NULL);
-  assert(serd_node_equals(&xnode, &SERD_NODE_NULL));
+  assert(serd_env_expand(env, NULL, &prefix, &suffix) == SERD_BAD_CURIE);
 
-  SerdNode xu = serd_env_expand_node(env, &u);
-  assert(!strcmp(xu.buf, "http://example.org/foo"));
-  serd_node_free(&xu);
+  assert(!serd_env_expand_node(NULL, u));
+  assert(!serd_env_expand_node(env, b));
+  assert(!serd_env_expand_node(env, s));
 
-  SerdNode badpre  = serd_node_from_string(SERD_CURIE, "hm:what");
-  SerdNode xbadpre = serd_env_expand_node(env, &badpre);
-  assert(serd_node_equals(&xbadpre, &SERD_NODE_NULL));
+  assert(!serd_env_set_base_uri(env, NULL));
 
-  SerdNode xc = serd_env_expand_node(env, &c);
-  assert(!strcmp(xc.buf, "http://example.org/b"));
-  serd_node_free(&xc);
+  SerdNode* xu = serd_env_expand_node(env, u);
+  assert(!strcmp(serd_node_string(xu), "http://example.org/foo"));
+  serd_node_free(xu);
 
-  assert(serd_env_set_prefix(env, &SERD_NODE_NULL, &SERD_NODE_NULL));
+  SerdNode* badpre  = serd_new_string(SERD_CURIE, "hm:what");
+  SerdNode* xbadpre = serd_env_expand_node(env, badpre);
+  assert(!xbadpre);
 
-  const SerdNode lit = serd_node_from_string(SERD_LITERAL, "hello");
-  assert(serd_env_set_prefix(env, &b, &lit));
+  SerdNode* xc = serd_env_expand_node(env, c);
+  assert(!strcmp(serd_node_string(xc), "http://example.org/b"));
+  serd_node_free(xc);
 
-  assert(!serd_env_new(&lit));
+  SerdNode* lit = serd_new_string(SERD_LITERAL, "hello");
+  assert(serd_env_set_prefix(env, b, lit));
 
-  const SerdNode blank  = serd_node_from_string(SERD_BLANK, "b1");
-  const SerdNode xblank = serd_env_expand_node(env, &blank);
-  assert(serd_node_equals(&xblank, &SERD_NODE_NULL));
+  SerdNode* blank = serd_new_string(SERD_BLANK, "b1");
+  assert(!serd_env_expand_node(env, blank));
+  serd_node_free(blank);
 
   int n_prefixes = 0;
   serd_env_set_prefix_from_strings(env, "eg.2", "http://example.org/");
   serd_env_foreach(env, count_prefixes, &n_prefixes);
   assert(n_prefixes == 1);
 
-  SerdNode shorter_uri = serd_node_from_string(SERD_URI, "urn:foo");
-  SerdNode prefix_name;
-  assert(!serd_env_qualify(env, &shorter_uri, &prefix_name, &suffix));
+  SerdNode* shorter_uri = serd_new_string(SERD_URI, "urn:foo");
+  assert(!serd_env_qualify(env, shorter_uri, &prefix_node, &suffix));
 
-  assert(!serd_env_set_base_uri(env, &u));
-  assert(serd_node_equals(serd_env_base_uri(env, NULL), &u));
+  assert(!serd_env_set_base_uri(env, u));
+  assert(serd_node_equals(serd_env_base_uri(env, NULL), u));
   assert(!serd_env_set_base_uri(env, NULL));
-  assert(!serd_env_base_uri(env, NULL)->buf);
+  assert(!serd_env_base_uri(env, NULL));
+
+  serd_node_free(shorter_uri);
+  serd_node_free(lit);
+  serd_node_free(badpre);
+  serd_node_free(s);
+  serd_node_free(c);
+  serd_node_free(b);
+  serd_node_free(u);
 
   serd_env_free(env);
 }
diff --git a/test/test_node.c b/test/test_node.c
index 21ef6feb..937d8a5f 100644
--- a/test/test_node.c
+++ b/test/test_node.c
@@ -6,6 +6,7 @@
 #include "serd/memory.h"
 #include "serd/node.h"
 #include "serd/string.h"
+#include "serd/uri.h"
 
 #include <assert.h>
 #include <float.h>
@@ -80,14 +81,14 @@ test_double_to_node(void)
                                  NULL};
 
   for (size_t i = 0; i < sizeof(dbl_test_nums) / sizeof(double); ++i) {
-    SerdNode   node = serd_new_decimal(dbl_test_nums[i], 8);
-    const bool pass = (node.buf && dbl_test_strs[i])
-                        ? !strcmp(node.buf, dbl_test_strs[i])
-                        : (node.buf == dbl_test_strs[i]);
+    SerdNode*   node     = serd_new_decimal(dbl_test_nums[i], 8);
+    const char* node_str = node ? serd_node_string(node) : NULL;
+    const bool  pass     = (node_str && dbl_test_strs[i])
+                             ? !strcmp(node_str, dbl_test_strs[i])
+                             : (node_str == dbl_test_strs[i]);
     assert(pass);
-    const size_t len = node.buf ? strlen(node.buf) : 0;
-    assert(node.n_bytes == len);
-    serd_node_free(&node);
+    assert(!node || serd_node_length(node) == strlen(node_str));
+    serd_node_free(node);
   }
 }
 
@@ -102,10 +103,11 @@ test_integer_to_node(void)
     "0", "0", "-23", "23", "-12340", "1000", "-1000"};
 
   for (size_t i = 0; i < N_TEST_NUMS; ++i) {
-    SerdNode node = serd_new_integer(int_test_nums[i]);
-    assert(!strcmp(node.buf, int_test_strs[i]));
-    assert(node.n_bytes == strlen(node.buf));
-    serd_node_free(&node);
+    SerdNode*   node     = serd_new_integer(int_test_nums[i]);
+    const char* node_str = serd_node_string(node);
+    assert(!strcmp(node_str, int_test_strs[i]));
+    assert(serd_node_length(node) == strlen(node_str));
+    serd_node_free(node);
   }
 
 #undef N_TEST_NUMS
@@ -114,26 +116,28 @@ test_integer_to_node(void)
 static void
 test_blob_to_node(void)
 {
+  assert(!serd_new_blob(&SERD_URI_NULL, 0, false));
+
   for (size_t size = 1; size < 256; ++size) {
     uint8_t* const data = (uint8_t*)malloc(size);
     for (size_t i = 0; i < size; ++i) {
       data[i] = (uint8_t)((size + i) % 256);
     }
 
-    SerdNode blob = serd_new_blob(data, size, size % 5);
-
-    assert(blob.n_bytes == strlen(blob.buf));
+    size_t      out_size = 0;
+    SerdNode*   blob     = serd_new_blob(data, size, size % 5);
+    const char* blob_str = serd_node_string(blob);
+    uint8_t*    out =
+      (uint8_t*)serd_base64_decode(blob_str, serd_node_length(blob), &out_size);
 
-    size_t   out_size = 0;
-    uint8_t* out =
-      (uint8_t*)serd_base64_decode(blob.buf, blob.n_bytes, &out_size);
+    assert(serd_node_length(blob) == strlen(blob_str));
     assert(out_size == size);
 
     for (size_t i = 0; i < size; ++i) {
       assert(out[i] == data[i]);
     }
 
-    serd_node_free(&blob);
+    serd_node_free(blob);
     serd_free(out);
     free(data);
   }
@@ -143,46 +147,45 @@ static void
 test_node_equals(void)
 {
   const uint8_t replacement_char_str[] = {0xEF, 0xBF, 0xBD, 0};
-  SerdNode      lhs =
-    serd_node_from_string(SERD_LITERAL, (const char*)replacement_char_str);
-  SerdNode rhs = serd_node_from_string(SERD_LITERAL, "123");
-  assert(!serd_node_equals(&lhs, &rhs));
+  SerdNode*     lhs =
+    serd_new_string(SERD_LITERAL, (const char*)replacement_char_str);
+  SerdNode* rhs = serd_new_string(SERD_LITERAL, "123");
+  assert(!serd_node_equals(lhs, rhs));
+
+  SerdNode* qnode = serd_new_string(SERD_CURIE, "foo:bar");
+  assert(!serd_node_equals(lhs, qnode));
+  assert(serd_node_equals(lhs, lhs));
 
-  SerdNode qnode = serd_node_from_string(SERD_CURIE, "foo:bar");
-  assert(!serd_node_equals(&lhs, &qnode));
-  assert(serd_node_equals(&lhs, &lhs));
+  assert(!serd_node_copy(NULL));
 
-  SerdNode null_copy = serd_node_copy(&SERD_NODE_NULL);
-  assert(serd_node_equals(&SERD_NODE_NULL, &null_copy));
+  serd_node_free(qnode);
+  serd_node_free(lhs);
+  serd_node_free(rhs);
 }
 
 static void
 test_node_from_string(void)
 {
-  SerdNode node = serd_node_from_string(SERD_LITERAL, "hello\"");
-  assert(node.n_bytes == 6 && node.flags == SERD_HAS_QUOTE &&
-         !strcmp(node.buf, "hello\""));
+  SerdNode* hello = serd_new_string(SERD_LITERAL, "hello\"");
+  assert(serd_node_length(hello) == 6 &&
+         serd_node_flags(hello) == SERD_HAS_QUOTE &&
+         !strcmp(serd_node_string(hello), "hello\""));
 
-  assert(node.n_bytes == 6 && node.flags == SERD_HAS_QUOTE &&
-         !strcmp((const char*)node.buf, "hello\""));
-
-  node = serd_node_from_string(SERD_URI, NULL);
-  assert(serd_node_equals(&node, &SERD_NODE_NULL));
+  serd_node_free(hello);
 }
 
 static void
 test_node_from_substring(void)
 {
-  SerdNode empty = serd_node_from_substring(SERD_LITERAL, NULL, 32);
-  assert(!empty.buf && !empty.n_bytes && !empty.flags && !empty.type);
-
-  SerdNode a_b = serd_node_from_substring(SERD_LITERAL, "a\"bc", 3);
-  assert(a_b.n_bytes == 3 && a_b.flags == SERD_HAS_QUOTE &&
-         !strncmp(a_b.buf, "a\"b", 3));
-
-  a_b = serd_node_from_substring(SERD_LITERAL, "a\"bc", 10);
-  assert(a_b.n_bytes == 4 && a_b.flags == SERD_HAS_QUOTE &&
-         !strncmp(a_b.buf, "a\"bc", 4));
+  SerdNode* a_b = serd_new_substring(SERD_LITERAL, "a\"bc", 3);
+  assert(serd_node_length(a_b) == 3 && serd_node_flags(a_b) == SERD_HAS_QUOTE &&
+         !strncmp(serd_node_string(a_b), "a\"b", 3));
+
+  serd_node_free(a_b);
+  a_b = serd_new_substring(SERD_LITERAL, "a\"bc", 10);
+  assert(serd_node_length(a_b) == 4 && serd_node_flags(a_b) == SERD_HAS_QUOTE &&
+         !strncmp(serd_node_string(a_b), "a\"bc", 4));
+  serd_node_free(a_b);
 }
 
 int
diff --git a/test/test_reader_writer.c b/test/test_reader_writer.c
index f6dfe512..5aa2b850 100644
--- a/test/test_reader_writer.c
+++ b/test/test_reader_writer.c
@@ -458,25 +458,21 @@ test_writer(const char* const path)
   serd_writer_chop_blank_prefix(writer, "tmp");
   serd_writer_chop_blank_prefix(writer, NULL);
 
-  const SerdNode lit = serd_node_from_string(SERD_LITERAL, "hello");
+  SerdNode* lit = serd_new_string(SERD_LITERAL, "hello");
 
-  assert(serd_writer_set_base_uri(writer, &lit));
-  assert(serd_writer_set_prefix(writer, &lit, &lit));
+  assert(serd_writer_set_base_uri(writer, lit));
+  assert(serd_writer_set_prefix(writer, lit, lit));
   assert(serd_writer_end_anon(writer, NULL));
   assert(serd_writer_env(writer) == env);
 
-  uint8_t  buf[] = {0xEF, 0xBF, 0xBD, 0};
-  SerdNode s     = serd_node_from_string(SERD_URI, "");
-  SerdNode p     = serd_node_from_string(SERD_URI, "http://example.org/pred");
-  SerdNode o     = serd_node_from_string(SERD_LITERAL, (char*)buf);
+  uint8_t   buf[] = {0xEF, 0xBF, 0xBD, 0};
+  SerdNode* s     = serd_new_string(SERD_URI, "");
+  SerdNode* p     = serd_new_string(SERD_URI, "http://example.org/pred");
+  SerdNode* o     = serd_new_string(SERD_LITERAL, (char*)buf);
 
   // Write 3 invalid statements (should write nothing)
-  const SerdNode* junk[][5] = {{&s, &p, &SERD_NODE_NULL, NULL, NULL},
-                               {&s, &SERD_NODE_NULL, &o, NULL, NULL},
-                               {&SERD_NODE_NULL, &p, &o, NULL, NULL},
-                               {&s, &o, &o, NULL, NULL},
-                               {&o, &p, &o, NULL, NULL},
-                               {&s, &p, &SERD_NODE_NULL, NULL, NULL}};
+  const SerdNode* junk[][5] = {
+    {s, o, o, NULL, NULL}, {o, p, o, NULL, NULL}, {s, o, p, NULL, NULL}};
   for (size_t i = 0; i < sizeof(junk) / (sizeof(SerdNode*) * 5); ++i) {
     assert(serd_writer_write_statement(writer,
                                        0,
@@ -488,18 +484,18 @@ test_writer(const char* const path)
                                        junk[i][4]));
   }
 
-  const SerdNode  t         = serd_node_from_string(SERD_URI, "urn:Type");
-  const SerdNode  l         = serd_node_from_string(SERD_LITERAL, "en");
-  const SerdNode* good[][5] = {{&s, &p, &o, NULL, NULL},
-                               {&s, &p, &o, &SERD_NODE_NULL, &SERD_NODE_NULL},
-                               {&s, &p, &o, &t, NULL},
-                               {&s, &p, &o, NULL, &l},
-                               {&s, &p, &o, &t, &l},
-                               {&s, &p, &o, &t, &SERD_NODE_NULL},
-                               {&s, &p, &o, &SERD_NODE_NULL, &l},
-                               {&s, &p, &o, NULL, &SERD_NODE_NULL},
-                               {&s, &p, &o, &SERD_NODE_NULL, NULL},
-                               {&s, &p, &o, &SERD_NODE_NULL, NULL}};
+  SerdNode*       t         = serd_new_string(SERD_URI, "urn:Type");
+  SerdNode*       l         = serd_new_string(SERD_LITERAL, "en");
+  const SerdNode* good[][5] = {{s, p, o, NULL, NULL},
+                               {s, p, o, NULL, NULL},
+                               {s, p, o, t, NULL},
+                               {s, p, o, NULL, l},
+                               {s, p, o, t, l},
+                               {s, p, o, t, NULL},
+                               {s, p, o, NULL, l},
+                               {s, p, o, NULL, NULL},
+                               {s, p, o, NULL, NULL},
+                               {s, p, o, NULL, NULL}};
   for (size_t i = 0; i < sizeof(good) / (sizeof(SerdNode*) * 5); ++i) {
     assert(!serd_writer_write_statement(writer,
                                         0,
@@ -512,53 +508,44 @@ test_writer(const char* const path)
   }
 
   // Write statements with bad UTF-8 (should be replaced)
-  const uint8_t bad_str[] = {0xFF, 0x90, 'h', 'i', 0};
-  SerdNode bad_lit = serd_node_from_string(SERD_LITERAL, (const char*)bad_str);
-  SerdNode bad_uri = serd_node_from_string(SERD_URI, (const char*)bad_str);
-  assert(!serd_writer_write_statement(
-    writer, 0, NULL, &s, &p, &bad_lit, NULL, NULL));
-  assert(!serd_writer_write_statement(
-    writer, 0, NULL, &s, &p, &bad_uri, NULL, NULL));
+  const char bad_str[] = {(char)0xFF, (char)0x90, 'h', 'i', 0};
+  SerdNode*  bad_lit   = serd_new_string(SERD_LITERAL, bad_str);
+  SerdNode*  bad_uri   = serd_new_string(SERD_URI, bad_str);
+  assert(
+    !serd_writer_write_statement(writer, 0, NULL, s, p, bad_lit, NULL, NULL));
+  assert(
+    !serd_writer_write_statement(writer, 0, NULL, s, p, bad_uri, NULL, NULL));
+  serd_node_free(bad_lit);
+  serd_node_free(bad_uri);
 
   // Write 1 valid statement
-  o = serd_node_from_string(SERD_LITERAL, "hello");
-  assert(!serd_writer_write_statement(writer, 0, NULL, &s, &p, &o, NULL, NULL));
+  serd_node_free(o);
+  o = serd_new_string(SERD_LITERAL, "hello");
+  assert(!serd_writer_write_statement(writer, 0, NULL, s, p, o, NULL, NULL));
 
   serd_writer_free(writer);
+  serd_node_free(lit);
+  serd_node_free(o);
+  serd_node_free(t);
+  serd_node_free(l);
 
   // Test buffer sink
   SerdBuffer buffer = {NULL, 0};
   writer =
     serd_writer_new(SERD_TURTLE, 0, env, NULL, serd_buffer_sink, &buffer);
 
-  o = serd_node_from_string(SERD_URI, "http://example.org/base");
-  assert(!serd_writer_set_base_uri(writer, &o));
+  o = serd_new_string(SERD_URI, "http://example.org/base");
+  assert(!serd_writer_set_base_uri(writer, o));
 
+  serd_node_free(o);
   serd_writer_free(writer);
   char* out = serd_buffer_sink_finish(&buffer);
 
   assert(!strcmp(out, "@base <http://example.org/base> .\n"));
   serd_free(out);
 
-  // Test writing empty node
-  SerdNode nothing = serd_node_from_string(SERD_NOTHING, "");
-
-  buffer.buf = NULL;
-  buffer.len = 0;
-  writer =
-    serd_writer_new(SERD_TURTLE, 0U, env, NULL, serd_buffer_sink, &buffer);
-
-  assert(!serd_writer_write_statement(
-    writer, 0, NULL, &s, &p, &nothing, NULL, NULL));
-
-  assert(
-    !strncmp((const char*)buffer.buf, "<>\n\t<http://example.org/pred> ", 30));
-
-  serd_writer_free(writer);
-  out = serd_buffer_sink_finish(&buffer);
-
-  assert(!strcmp((const char*)out, "<>\n\t<http://example.org/pred>  .\n"));
-  serd_free(out);
+  serd_node_free(p);
+  serd_node_free(s);
 
   serd_env_free(env);
   fclose(fd);
@@ -581,8 +568,8 @@ test_reader(const char* path)
 
   assert(serd_reader_read_chunk(reader) == SERD_FAILURE);
 
-  SerdNode g = serd_node_from_string(SERD_URI, "http://example.org/");
-  serd_reader_set_default_graph(reader, &g);
+  SerdNode* g = serd_new_string(SERD_URI, "http://example.org/");
+  serd_reader_set_default_graph(reader, g);
   serd_reader_add_blank_prefix(reader, "tmp");
 
 #if defined(__GNUC__)
@@ -594,6 +581,8 @@ test_reader(const char* path)
 #  pragma GCC diagnostic pop
 #endif
 
+  serd_node_free(g);
+
   assert(serd_reader_read_file(reader, "http://notafile"));
   assert(serd_reader_read_file(reader, "file:///better/not/exist"));
   assert(serd_reader_read_file(reader, "file://"));
@@ -604,8 +593,8 @@ test_reader(const char* path)
   assert(rt->n_prefix == 0);
   assert(rt->n_statement == 13);
   assert(rt->n_end == 0);
-  assert(rt->graph && rt->graph->buf &&
-         !strcmp(rt->graph->buf, "http://example.org/"));
+  assert(rt->graph && serd_node_string(rt->graph) &&
+         !strcmp(serd_node_string(rt->graph), "http://example.org/"));
 
   assert(serd_reader_read_string(reader, "This isn't Turtle at all."));
 
diff --git a/test/test_uri.c b/test/test_uri.c
index d3ba5514..0942439f 100644
--- a/test/test_uri.c
+++ b/test/test_uri.c
@@ -44,17 +44,18 @@ test_file_uri(const char* const hostname,
     expected_path = path;
   }
 
-  SerdNode node         = serd_new_file_uri(path, hostname, 0);
-  char*    out_hostname = NULL;
-  char*    out_path     = serd_file_uri_parse(node.buf, &out_hostname);
-  assert(!strcmp(node.buf, expected_uri));
+  SerdNode*   node         = serd_new_file_uri(path, hostname, 0);
+  const char* node_str     = serd_node_string(node);
+  char*       out_hostname = NULL;
+  char*       out_path     = serd_file_uri_parse(node_str, &out_hostname);
+  assert(!strcmp(node_str, expected_uri));
   assert((hostname && out_hostname) || (!hostname && !out_hostname));
   assert(!hostname || !strcmp(hostname, out_hostname));
   assert(!strcmp(out_path, expected_path));
 
   serd_free(out_path);
   serd_free(out_hostname);
-  serd_node_free(&node);
+  serd_node_free(node);
 }
 
 static void
@@ -114,22 +115,20 @@ test_uri_parsing(void)
 static void
 test_uri_from_string(void)
 {
-  SerdNode nonsense = serd_new_uri_from_string(NULL, NULL, NULL);
-  assert(nonsense.type == SERD_NOTHING);
+  assert(!serd_new_uri_from_string(NULL, NULL, NULL));
 
   SerdURIView base_uri;
-  SerdNode    base =
+  SerdNode*   base =
     serd_new_uri_from_string("http://example.org/", NULL, &base_uri);
-  SerdNode nil  = serd_new_uri_from_string(NULL, &base_uri, NULL);
-  SerdNode nil2 = serd_new_uri_from_string("", &base_uri, NULL);
-  assert(nil.type == SERD_URI);
-  assert(!strcmp(nil.buf, base.buf));
-  assert(nil2.type == SERD_URI);
-  assert(!strcmp(nil2.buf, base.buf));
-  serd_node_free(&nil);
-  serd_node_free(&nil2);
-
-  serd_node_free(&base);
+  SerdNode* nil  = serd_new_uri_from_string(NULL, &base_uri, NULL);
+  SerdNode* nil2 = serd_new_uri_from_string("", &base_uri, NULL);
+  assert(serd_node_type(nil) == SERD_URI);
+  assert(!strcmp(serd_node_string(nil), serd_node_string(base)));
+  assert(serd_node_type(nil2) == SERD_URI);
+  assert(!strcmp(serd_node_string(nil2), serd_node_string(base)));
+  serd_node_free(nil);
+  serd_node_free(nil2);
+  serd_node_free(base);
 }
 
 static inline bool
@@ -154,21 +153,21 @@ check_relative_uri(const char* const uri_string,
   SerdURIView base   = SERD_URI_NULL;
   SerdURIView result = SERD_URI_NULL;
 
-  SerdNode uri_node  = serd_new_uri_from_string(uri_string, NULL, &uri);
-  SerdNode base_node = serd_new_uri_from_string(base_string, NULL, &base);
+  SerdNode* uri_node  = serd_new_uri_from_string(uri_string, NULL, &uri);
+  SerdNode* base_node = serd_new_uri_from_string(base_string, NULL, &base);
 
-  SerdNode result_node = SERD_NODE_NULL;
+  SerdNode* result_node = NULL;
   if (root_string) {
     SerdURIView root      = SERD_URI_NULL;
-    SerdNode    root_node = serd_new_uri_from_string(root_string, NULL, &root);
+    SerdNode*   root_node = serd_new_uri_from_string(root_string, NULL, &root);
 
     result_node = serd_new_relative_uri(&uri, &base, &root, &result);
-    serd_node_free(&root_node);
+    serd_node_free(root_node);
   } else {
     result_node = serd_new_relative_uri(&uri, &base, NULL, &result);
   }
 
-  assert(!strcmp((const char*)result_node.buf, expected_string));
+  assert(!strcmp(serd_node_string(result_node), expected_string));
 
   SerdURIView expected = SERD_URI_NULL;
   assert(!serd_uri_parse(expected_string, &expected));
@@ -179,9 +178,9 @@ check_relative_uri(const char* const uri_string,
   assert(chunk_equals(&result.query, &expected.query));
   assert(chunk_equals(&result.fragment, &expected.fragment));
 
-  serd_node_free(&result_node);
-  serd_node_free(&base_node);
-  serd_node_free(&uri_node);
+  serd_node_free(result_node);
+  serd_node_free(base_node);
+  serd_node_free(uri_node);
 }
 
 static void
diff --git a/test/test_writer.c b/test/test_writer.c
index 6a7a35b5..9d004076 100644
--- a/test/test_writer.c
+++ b/test/test_writer.c
@@ -27,12 +27,15 @@ test_write_long_literal(void)
 
   assert(writer);
 
-  SerdNode s = serd_node_from_string(SERD_URI, "http://example.org/s");
-  SerdNode p = serd_node_from_string(SERD_URI, "http://example.org/p");
-  SerdNode o = serd_node_from_string(SERD_LITERAL, "hello \"\"\"world\"\"\"!");
+  SerdNode* s = serd_new_string(SERD_URI, "http://example.org/s");
+  SerdNode* p = serd_new_string(SERD_URI, "http://example.org/p");
+  SerdNode* o = serd_new_string(SERD_LITERAL, "hello \"\"\"world\"\"\"!");
 
-  assert(!serd_writer_write_statement(writer, 0, NULL, &s, &p, &o, NULL, NULL));
+  assert(!serd_writer_write_statement(writer, 0, NULL, s, p, o, NULL, NULL));
 
+  serd_node_free(o);
+  serd_node_free(p);
+  serd_node_free(s);
   serd_writer_free(writer);
   serd_env_free(env);
 
@@ -63,12 +66,12 @@ test_writer_cleanup(void)
   SerdWriter* writer =
     serd_writer_new(SERD_TURTLE, 0U, env, NULL, null_sink, NULL);
 
-  SerdNode s = serd_node_from_string(SERD_URI, "http://example.org/s");
-  SerdNode p = serd_node_from_string(SERD_URI, "http://example.org/p");
-  SerdNode o = serd_node_from_string(SERD_BLANK, "http://example.org/o");
+  SerdNode* s = serd_new_string(SERD_URI, "http://example.org/s");
+  SerdNode* p = serd_new_string(SERD_URI, "http://example.org/p");
+  SerdNode* o = serd_new_string(SERD_BLANK, "http://example.org/o");
 
   st = serd_writer_write_statement(
-    writer, SERD_ANON_O_BEGIN, NULL, &s, &p, &o, NULL, NULL);
+    writer, SERD_ANON_O_BEGIN, NULL, s, p, o, NULL, NULL);
 
   assert(!st);
 
@@ -77,11 +80,12 @@ test_writer_cleanup(void)
     char buf[12] = {0};
     snprintf(buf, sizeof(buf), "b%u", i);
 
-    SerdNode next_o = serd_node_from_string(SERD_BLANK, buf);
+    SerdNode* next_o = serd_new_string(SERD_BLANK, buf);
 
     st = serd_writer_write_statement(
-      writer, SERD_ANON_O_BEGIN, NULL, &o, &p, &next_o, NULL, NULL);
+      writer, SERD_ANON_O_BEGIN, NULL, o, p, next_o, NULL, NULL);
 
+    serd_node_free(o);
     o = next_o;
   }
 
@@ -92,6 +96,9 @@ test_writer_cleanup(void)
   assert(!(st = serd_writer_set_base_uri(writer, NULL)));
 
   // Free (which could leak if the writer doesn't clean up the stack properly)
+  serd_node_free(o);
+  serd_node_free(p);
+  serd_node_free(s);
   serd_writer_free(writer);
   serd_env_free(env);
 }
@@ -111,18 +118,22 @@ test_strict_write(void)
 
   const uint8_t bad_str[] = {0xFF, 0x90, 'h', 'i', 0};
 
-  SerdNode s = serd_node_from_string(SERD_URI, "http://example.org/s");
-  SerdNode p = serd_node_from_string(SERD_URI, "http://example.org/p");
+  SerdNode* s = serd_new_string(SERD_URI, "http://example.org/s");
+  SerdNode* p = serd_new_string(SERD_URI, "http://example.org/p");
 
-  SerdNode bad_lit = serd_node_from_string(SERD_LITERAL, (const char*)bad_str);
-  SerdNode bad_uri = serd_node_from_string(SERD_URI, (const char*)bad_str);
+  SerdNode* bad_lit = serd_new_string(SERD_LITERAL, (const char*)bad_str);
+  SerdNode* bad_uri = serd_new_string(SERD_URI, (const char*)bad_str);
 
   assert(serd_writer_write_statement(
-           writer, 0, NULL, &s, &p, &bad_lit, NULL, NULL) == SERD_BAD_TEXT);
+           writer, 0, NULL, s, p, bad_lit, NULL, NULL) == SERD_BAD_TEXT);
 
   assert(serd_writer_write_statement(
-           writer, 0, NULL, &s, &p, &bad_uri, NULL, NULL) == SERD_BAD_TEXT);
+           writer, 0, NULL, s, p, bad_uri, NULL, NULL) == SERD_BAD_TEXT);
 
+  serd_node_free(bad_uri);
+  serd_node_free(bad_lit);
+  serd_node_free(p);
+  serd_node_free(s);
   serd_writer_free(writer);
   serd_env_free(env);
   fclose(fd);
@@ -146,15 +157,16 @@ test_write_error(void)
   SerdWriter*    writer = NULL;
   SerdStatus     st     = SERD_SUCCESS;
 
-  SerdNode u = serd_node_from_string(SERD_URI, "http://example.com/u");
+  SerdNode* u = serd_new_string(SERD_URI, "http://example.com/u");
 
   writer = serd_writer_new(
     SERD_TURTLE, (SerdWriterFlags)0, env, NULL, error_sink, NULL);
   assert(writer);
-  st = serd_writer_write_statement(writer, 0U, NULL, &u, &u, &u, NULL, NULL);
+  st = serd_writer_write_statement(writer, 0U, NULL, u, u, u, NULL, NULL);
   assert(st == SERD_BAD_WRITE);
   serd_writer_free(writer);
 
+  serd_node_free(u);
   serd_env_free(env);
 }