CST-agent/tests/test_apply_patch.c

#define _POSIX_C_SOURCE 200809L

#include "cst_agent.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "cst_test_util.h"

static int nfail;

#define EXPECT(cond, msg)                                                      \
  do {                                                                         \
    if (!(cond)) {                                                             \
      fprintf(stderr, "FAIL %s:%d: %s\n", __FILE__, __LINE__, msg);            \
      nfail++;                                                                 \
    }                                                                          \
  } while (0)

static char *apply(const char *orig, const char *hunks, int *rc, int *nh,
                   char *err, size_t esz) {
  char *out = NULL;
  size_t out_len = 0;
  *rc = cst_patch_apply_buffer(orig, strlen(orig), hunks, strlen(hunks), &out,
                               &out_len, nh, err, esz);
  return out;
}

static void test_buffer_basic(void) {
  char err[256];
  int rc, nh;
  const char *orig = "a\nb\nc\nd\ne\n";
  char *out = apply(orig, "@@ -2,3 +2,3 @@\n b\n-c\n+C\n d\n", &rc, &nh, err,
                    sizeof(err));
  EXPECT(rc == 0 && nh == 1, "single hunk applies");
  EXPECT(out && strcmp(out, "a\nb\nC\nd\ne\n") == 0, "single hunk result");
  free(out);

  /* two hunks, the second located relative to the shift of the first */
  out = apply(orig, "@@ -1,2 +1,3 @@\n a\n+a2\n b\n@@ -4,2 +5,2 @@\n d\n-e\n+E\n",
              &rc, &nh, err, sizeof(err));
  EXPECT(rc == 0 && nh == 2, "two hunks apply");
  EXPECT(out && strcmp(out, "a\na2\nb\nc\nd\nE\n") == 0, "two hunk result");
  free(out);

  /* wrong line numbers: found by searching near the hint */
  out = apply(orig, "@@ -40,1 +40,1 @@\n-d\n+D\n", &rc, &nh, err, sizeof(err));
  EXPECT(rc == 0, "hint off: searched");
  EXPECT(out && strcmp(out, "a\nb\nc\nD\ne\n") == 0, "search result");
  free(out);

  /* bare @@ without numbers, unique context */
  out = apply(orig, "@@\n c\n-d\n+dd\n", &rc, &nh, err, sizeof(err));
  EXPECT(rc == 0 && out && strcmp(out, "a\nb\nc\ndd\ne\n") == 0, "bare @@");
  free(out);
}

static void test_buffer_edge(void) {
  char err[256];
  int rc, nh;
  /* ambiguous context without a line hint is refused */
  char *out = apply("x\ny\nx\ny\n", "@@\n-x\n+z\n", &rc, &nh, err, sizeof(err));
  EXPECT(rc != 0, "ambiguous refused");
  EXPECT(strstr(err, "ambiguous") != NULL, "ambiguous error text");
  free(out);

  /* the same hunk with a hint picks the hinted occurrence */
  out = apply("x\ny\nx\ny\n", "@@ -3,1 +3,1 @@\n-x\n+z\n", &rc, &nh, err,
              sizeof(err));
  EXPECT(rc == 0 && out && strcmp(out, "x\ny\nz\ny\n") == 0, "hinted occurrence");
  free(out);

  /* missing context fails and changes nothing (all-or-nothing) */
  out = apply("a\nb\n", "@@ -1,1 +1,1 @@\n-a\n+A\n@@ -9,1 +9,1 @@\n-zzz\n+q\n",
              &rc, &nh, err, sizeof(err));
  EXPECT(rc != 0 && out == NULL, "second hunk fails -> nothing");
  free(out);

  /* trailing whitespace drift is tolerated by the loose pass */
  out = apply("int x;   \nint y;\n", "@@ -1,2 +1,2 @@\n int x;\n-int y;\n+int z;\n",
              &rc, &nh, err, sizeof(err));
  EXPECT(rc == 0 && out && strstr(out, "int z;"), "rtrim-loose match");
  free(out);

  /* no final newline preserved / added */
  out = apply("a\nb", "@@ -2 +2 @@\n-b\n\\ No newline at end of file\n+B\n"
                      "\\ No newline at end of file\n",
              &rc, &nh, err, sizeof(err));
  EXPECT(rc == 0 && out && strcmp(out, "a\nB") == 0, "no final newline kept");
  free(out);

  /* a blank line inside a hunk is empty context (models drop the space) */
  out = apply("a\n\nb\n", "@@ -1,3 +1,3 @@\n a\n\n-b\n+B\n", &rc, &nh, err,
              sizeof(err));
  EXPECT(rc == 0 && out && strcmp(out, "a\n\nB\n") == 0, "blank context line");
  free(out);

  /* tabs survive */
  out = apply("all:\n\tgcc a.c\n", "@@ -2 +2 @@\n-\tgcc a.c\n+\tgcc -O2 a.c\n",
              &rc, &nh, err, sizeof(err));
  EXPECT(rc == 0 && out && strcmp(out, "all:\n\tgcc -O2 a.c\n") == 0, "tabs");
  free(out);
}

static char g_ws[256];

static void put(const char *rel, const char *content) {
  char p[512];
  snprintf(p, sizeof(p), "%s/%s", g_ws, rel);
  FILE *fp = fopen(p, "wb");
  fputs(content, fp);
  fclose(fp);
}

static char *get(const char *rel) {
  char p[512];
  snprintf(p, sizeof(p), "%s/%s", g_ws, rel);
  FILE *fp = fopen(p, "rb");
  if (!fp)
    return NULL;
  static char buf[8192];
  size_t n = fread(buf, 1, sizeof(buf) - 1, fp);
  buf[n] = 0;
  fclose(fp);
  return buf;
}

static int run_patch(const char *patch, cst_tool_result_t *r) {
  ctl_tool_call_t c;
  memset(&c, 0, sizeof(c));
  snprintf(c.id, sizeof(c.id), "t");
  snprintf(c.name, sizeof(c.name), "apply_patch");
  snprintf(c.args[0].key, sizeof(c.args[0].key), "patch");
  c.args[0].value = (char *)patch;
  c.args[0].value_len = strlen(patch);
  c.nargs = 1;
  memset(r, 0, sizeof(*r));
  cst_tool_dispatch(g_ws, &c, r);
  return r->exit_code;
}

static void test_tool_multi_file(void) {
  put("a.c", "int a = 1;\n");
  put("b.c", "int b = 2;\n");
  put("gone.c", "x\n");
  cst_tool_result_t r;
  int ec = run_patch("--- a/a.c\n+++ b/a.c\n@@ -1 +1 @@\n-int a = 1;\n+int a = 10;\n"
                     "--- a/b.c\n+++ b/b.c\n@@ -1 +1 @@\n-int b = 2;\n+int b = 20;\n"
                     "--- /dev/null\n+++ b/sub/dir/new.c\n@@ -0,0 +1,2 @@\n+one\n+two\n"
                     "--- a/gone.c\n+++ /dev/null\n@@ -1 +0,0 @@\n-x\n",
                     &r);
  EXPECT(ec == 0, "multi-file patch ok");
  if (ec != 0)
    fprintf(stderr, "%.*s\n", (int)r.out_len, r.out ? r.out : "");
  cst_tool_result_free(&r);
  char *s = get("a.c");
  EXPECT(s && strcmp(s, "int a = 10;\n") == 0, "a.c updated");
  s = get("b.c");
  EXPECT(s && strcmp(s, "int b = 20;\n") == 0, "b.c updated");
  s = get("sub/dir/new.c");
  EXPECT(s && strcmp(s, "one\ntwo\n") == 0, "new file with parent dirs");
  EXPECT(get("gone.c") == NULL, "deleted file");

  /* second file fails -> first file untouched */
  ec = run_patch("--- a/a.c\n+++ b/a.c\n@@ -1 +1 @@\n-int a = 10;\n+int a = 99;\n"
                 "--- a/b.c\n+++ b/b.c\n@@ -1 +1 @@\n-no such line\n+q\n",
                 &r);
  EXPECT(ec != 0, "failing multi-file patch reports error");
  cst_tool_result_free(&r);
  s = get("a.c");
  EXPECT(s && strcmp(s, "int a = 10;\n") == 0, "all-or-nothing across files");

  /* escaping the workspace is refused */
  ec = run_patch("--- /dev/null\n+++ b/../escape.c\n@@ -0,0 +1 @@\n+x\n", &r);
  EXPECT(ec != 0, "path escape refused");
  cst_tool_result_free(&r);
}

int main(void) {
  test_buffer_basic();
  test_buffer_edge();
  if (test_tmpdir(g_ws, sizeof(g_ws), "cst-patch-test") != 0) {
    perror("tmpdir");
    return 1;
  }
  test_tool_multi_file();
  if (test_rmrf(g_ws) != 0)
    fprintf(stderr, "warning: cleanup failed\n");
  if (nfail) {
    fprintf(stderr, "test_apply_patch: %d failed\n", nfail);
    return 1;
  }
  printf("test_apply_patch: OK\n");
  return 0;
}