Add manifest_rewriter class

1 files changed, 185 insertions, 0 deletions

diff --git a/tests/manifest-rewriter/driver.cxx b/tests/manifest-rewriter/driver.cxx
new file mode 100644
index 0000000..f206c22
--- /dev/null
+++ b/tests/manifest-rewriter/driver.cxx
@@ -0,0 +1,185 @@
+// file      : tests/manifest-rewriter/driver.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2018 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <cassert>
+
+#ifndef __cpp_lib_modules
+#include <vector>
+#include <string>
+#include <cstdint>   // uint64_t
+#include <utility>   // move()
+#include <iostream>
+#include <exception>
+#endif
+
+// Other includes.
+
+#ifdef __cpp_modules
+#ifdef __cpp_lib_modules
+import std.core;
+import std.io;
+#endif
+import butl.path;
+import butl.optional;
+import butl.fdstream;
+import butl.manifest_parser;
+import butl.manifest_rewriter;
+#else
+#include <libbutl/path.mxx>
+#include <libbutl/optional.mxx>
+#include <libbutl/fdstream.mxx>
+#include <libbutl/manifest-parser.mxx>
+#include <libbutl/manifest-rewriter.mxx>
+#endif
+
+using namespace std;
+
+namespace butl
+{
+  using butl::optional;
+  using butl::nullopt;
+
+  // Value rewriting or insertion command.
+  //
+  struct edit_cmd
+  {
+    string name;
+    string value;
+    optional<string> after; // Rewrite an existing value if nullopt.
+
+    edit_cmd (string n, string v)
+        : name (move (n)), value (move (v)) {}
+
+    edit_cmd (string n, string v, string a)
+        : name (move (n)), value (move (v)), after (move (a)) {}
+  };
+
+  using edit_cmds = vector<edit_cmd>;
+
+  // Dump the manifest into the file, edit and return the resulting manifest.
+  //
+  // The file will stay in the filesystem for troubleshooting in case of an
+  // assertion failure and will be deleted otherwise.
+  //
+  static path temp_file (path::temp_path ("butl-manifest-rewriter"));
+
+  static string
+  edit (const char* manifest, const edit_cmds&);
+
+  int
+  main ()
+  {
+    auto_rmfile rm (temp_file);
+
+    assert (edit (":1\n# Comment\n# Comment\n a : b \n# Comment\n\nc:d\n",
+                  {{"a", "xyz"}}) ==
+            ":1\n# Comment\n# Comment\n a : xyz\n# Comment\n\nc:d\n");
+
+    assert (edit (":1\n\n a: b\n", {{"a", "xyz"}}) == ":1\n\n a: xyz\n");
+    assert (edit (":1\na: b", {{"a", "xyz"}}) == ":1\na: xyz");
+
+    assert (edit (":1\na:b\nc:d\ne:f",
+                  {{"a", "xyz"}, edit_cmd {"x", "y", "c"}, {"e", "123"}}) ==
+            ":1\na: xyz\nc:d\nx: y\ne: 123");
+
+    assert (edit (":1\na: b", {{"a", "xy\nz"}}) == ":1\na: \\\nxy\nz\n\\");
+
+    assert (edit (":1\n", {{"a", "b", ""}}) == ":1\na: b\n");
+
+    assert (edit (":1\n                                     abc: b",
+                  {{"abc", "xyz"}}) ==
+            ":1\n                                     abc: \\\nxyz\n\\");
+
+    // Test editing of manifests that contains CR characters.
+    //
+    assert (edit (":1\r\na: b\r\r\n", {{"a", "xyz"}}) == ":1\r\na: xyz\r\r\n");
+
+    assert (edit (":1\ra: b\r", {{"a", "xyz"}}) == ":1\ra: xyz\r");
+
+    assert (edit (":1\na: \\s", {{"a", "xyz"}}) == ":1\na: xyz");
+
+    assert (edit (":1\na: \\\nx\ny\nz\n\\\r", {{"a", "b"}}) == ":1\na: b\r");
+
+    return 0;
+  }
+
+  static string
+  edit (const char* manifest, const edit_cmds& cmds)
+  {
+    {
+      ofdstream os (temp_file);
+      os << manifest;
+      os.close ();
+    }
+
+    struct insertion
+    {
+      manifest_name_value value;
+      optional<manifest_name_value> pos; // Rewrite existing value if nullopt.
+    };
+
+    vector<insertion> insertions;
+    {
+      ifdstream is (temp_file);
+      manifest_parser p (is, temp_file.string ());
+
+      for (manifest_name_value nv; !(nv = p.next ()).empty (); )
+      {
+        for (const edit_cmd& c: cmds)
+        {
+          if (c.after)
+          {
+            if (nv.name == *c.after)
+            {
+              // Note: new value lines, columns and positions are all zero as
+              // are not used for an insertion.
+              //
+              insertions.push_back (
+                insertion {
+                  manifest_name_value {c.name, c.value, 0, 0, 0, 0, 0, 0, 0},
+                    move (nv)});
+
+              break;
+            }
+          }
+          else if (nv.name == c.name)
+          {
+            nv.value = c.value;
+            insertions.push_back (insertion {move (nv), nullopt /* pos */});
+            break;
+          }
+        }
+      }
+    }
+
+    {
+      manifest_rewriter rw (temp_file);
+
+      for (const auto& ins: reverse_iterate (insertions))
+      {
+        if (ins.pos)
+          rw.insert (*ins.pos, ins.value);
+        else
+          rw.replace (ins.value);
+      }
+    }
+
+    ifdstream is (temp_file);
+    return is.read_text ();
+  }
+}
+
+int
+main ()
+{
+  try
+  {
+    return butl::main ();
+  }
+  catch (const exception& e)
+  {
+    cerr << e << endl;
+    return 1;
+  }
+}