Strengthen exhaustive write error test

Factor out the check, then also check that writing with enough space succeeds.
This makes the test more future-proof since it will fail if the maximum sizes
aren't updated (meaning errors near the end of the document aren't covered).

Strengthen the check itself by including the status of serd_writer_finish(),
and bump the Turtle and TriG sizes by the three corresponding trailing bytes.

1 files changed, 45 insertions, 29 deletions

diff --git a/test/test_reader_writer.c b/test/test_reader_writer.c
index 8f432767..49821242 100644
--- a/test/test_reader_writer.c
+++ b/test/test_reader_writer.c
@@ -103,42 +103,58 @@ quiet_error_sink(void* const handle, const SerdError* const e)
 }
 
 static void
-test_write_errors(void)
+check_write_error_offset(const SerdSyntax syntax,
+                         const size_t     offset,
+                         const SerdStatus expected_status)
 {
-  ErrorContext    ctx   = {0U, 0U};
+  ErrorContext    ctx   = {0U, offset};
   const SerdStyle style = (SerdStyle)(SERD_STYLE_STRICT | SERD_STYLE_CURIED);
+  SerdEnv* const  env   = serd_env_new(NULL);
+  assert(env);
+
+  SerdWriter* const writer =
+    serd_writer_new(syntax, style, env, NULL, faulty_sink, &ctx);
+  assert(writer);
+
+  SerdReader* const reader =
+    serd_reader_new(SERD_TRIG,
+                    writer,
+                    NULL,
+                    (SerdBaseSink)serd_writer_set_base_uri,
+                    (SerdPrefixSink)serd_writer_set_prefix,
+                    (SerdStatementSink)serd_writer_write_statement,
+                    (SerdEndSink)serd_writer_end_anon);
+  assert(reader);
+
+  serd_writer_set_error_sink(writer, quiet_error_sink, NULL);
+  serd_reader_set_error_sink(reader, quiet_error_sink, NULL);
 
-  const size_t max_offsets[] = {0, 462, 1911, 2003, 462};
+  const SerdStatus rst = serd_reader_read_string(reader, USTR(doc_string));
+  const SerdStatus wst = serd_writer_finish(writer);
+
+  serd_reader_free(reader);
+  serd_writer_free(writer);
+  serd_env_free(env);
+
+  const SerdStatus st = rst ? rst : wst;
+  assert(st == expected_status);
+}
+
+static void
+test_write_errors(void)
+{
+  // Syntax-keyed array of output document sizes
+  static const size_t max_offsets[] = {0, 465, 1911, 2003, 465};
 
-  // Test errors at different offsets to hit different code paths
   for (unsigned s = 1; s <= (unsigned)SERD_TRIG; ++s) {
     const SerdSyntax syntax = (SerdSyntax)s;
+
+    // Check successfully writing with enough space
+    check_write_error_offset(syntax, max_offsets[s], SERD_SUCCESS);
+
+    // Check write error at every offset in the output
     for (size_t o = 0; o < max_offsets[s]; ++o) {
-      ctx.n_written    = 0;
-      ctx.error_offset = o;
-
-      SerdEnv* const    env = serd_env_new(NULL);
-      SerdWriter* const writer =
-        serd_writer_new(syntax, style, env, NULL, faulty_sink, &ctx);
-
-      SerdReader* const reader =
-        serd_reader_new(SERD_TRIG,
-                        writer,
-                        NULL,
-                        (SerdBaseSink)serd_writer_set_base_uri,
-                        (SerdPrefixSink)serd_writer_set_prefix,
-                        (SerdStatementSink)serd_writer_write_statement,
-                        (SerdEndSink)serd_writer_end_anon);
-
-      serd_reader_set_error_sink(reader, quiet_error_sink, NULL);
-      serd_writer_set_error_sink(writer, quiet_error_sink, NULL);
-
-      const SerdStatus st = serd_reader_read_string(reader, USTR(doc_string));
-      assert(st == SERD_ERR_BAD_WRITE);
-
-      serd_reader_free(reader);
-      serd_writer_free(writer);
-      serd_env_free(env);
+      check_write_error_offset(syntax, o, SERD_ERR_BAD_WRITE);
     }
   }
 }