Update test paths after flattening v0 layout

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

v0/buffer.c

@@ -0,0 +1,63 @@
+#include "buffer.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+typedef enum {
+	BUFFER_FILE,
+	BUFFER_STRING
+} BufferType;
+
+struct Buffer {
+	BufferType type;
+	union {
+		FILE* file;
+		struct {
+			const char* data;
+			size_t pos;
+		} string;
+	} source;
+};
+
+Buffer* buffer_open_file(const char* path) {
+	FILE* f = fopen(path, "r");
+	if (f == NULL)
+		return NULL;
+	Buffer* buf = malloc(sizeof(Buffer));
+	if (buf == NULL) {
+		fclose(f);
+		return NULL;
+	}
+	buf->type = BUFFER_FILE;
+	buf->source.file = f;
+	return buf;
+}
+
+Buffer* buffer_open_string(const char* string) {
+	Buffer* buf = malloc(sizeof(Buffer));
+	if (buf == NULL)
+		return NULL;
+	buf->type = BUFFER_STRING;
+	buf->source.string.data = string;
+	buf->source.string.pos = 0;
+	return buf;
+}
+
+void buffer_close(Buffer* buffer) {
+	if (buffer->type == BUFFER_FILE)
+		fclose(buffer->source.file);
+	free(buffer);
+}
+
+char buffer_read(Buffer* buffer) {
+	if (buffer->type == BUFFER_FILE) {
+		int c = fgetc(buffer->source.file);
+		return c == EOF ? (char)-1 : (char)c;
+	} else {
+		char c = buffer->source.string.data[buffer->source.string.pos];
+		if (c == '\0')
+			return (char)-1;
+		buffer->source.string.pos++;
+		return c;
+	}
+}