Merge #5535 from justinmk/api_level

api: Nvim version + API level

CMakeLists.txt

@@ -59,12 +59,17 @@ set_property(CACHE CMAKE_BUILD_TYPE PROPERTY
   STRINGS "Debug" "Dev" "Release" "MinSizeRel" "RelWithDebInfo")
 
 # If not in a git repo (e.g., a tarball) these tokens define the complete
-# version string, else it is combined with the result of `git describe`.
+# version string, else they are combined with the result of `git describe`.
 set(NVIM_VERSION_MAJOR 0)
 set(NVIM_VERSION_MINOR 1)
 set(NVIM_VERSION_PATCH 6)
 set(NVIM_VERSION_PRERELEASE "-dev") # for package maintainers
 
+# API level
+set(NVIM_API_LEVEL 1)         # Bump this after any API change.
+set(NVIM_API_LEVEL_COMPAT 0)  # Adjust this after a _breaking_ API change.
+set(NVIM_API_PRERELEASE true)
+
 file(TO_CMAKE_PATH ${CMAKE_CURRENT_LIST_DIR}/.git FORCED_GIT_DIR)
 include(GetGitRevisionDescription)
 get_git_head_revision(GIT_REFSPEC NVIM_VERSION_COMMIT)

config/versiondef.h.in

@@ -7,6 +7,10 @@
 #define NVIM_VERSION_PRERELEASE "@NVIM_VERSION_PRERELEASE@"
 #cmakedefine NVIM_VERSION_MEDIUM "@NVIM_VERSION_MEDIUM@"
 
+#define NVIM_API_LEVEL @NVIM_API_LEVEL@
+#define NVIM_API_LEVEL_COMPAT @NVIM_API_LEVEL_COMPAT@
+#define NVIM_API_PRERELEASE @NVIM_API_PRERELEASE@
+
 #define NVIM_VERSION_CFLAGS "@NVIM_VERSION_CFLAGS@"
 #define NVIM_VERSION_BUILD_TYPE "@NVIM_VERSION_BUILD_TYPE@"
 

runtime/doc/api.txt

@@ -51,9 +51,10 @@ Tabpage				  -> enum value kObjectTypeTabpage
 
 Nvim exposes metadata about the API as a Dictionary with the following keys:
 
-functions  	calling signature of the API functions
+version		Nvim version, API level/compatibility
-types		The custom handle types defined by Nvim
+functions  	API function signatures
-error_types	The possible kinds of errors an API function can exit with.
+types		Custom handle types defined by Nvim
+error_types	Possible error types returned by API functions
 
 This metadata is mostly useful for external programs accessing the API via
 RPC, see |rpc-api|.

runtime/doc/msgpack_rpc.txt

@@ -168,6 +168,8 @@ API metadata object ~
 API clients exist to hide msgpack-rpc details. The API metadata object
 contains information that makes this task easier (see also |rpc-types|):
 
+  - The "version" key contains the Nvim version, API level, and API
+    backwards-compatibility level.
   - The "functions" key contains a list of metadata objects for individual
     functions.
   - Each function metadata object has |rpc-types| information about the return

scripts/release.sh

@@ -5,6 +5,7 @@
 # Steps:
 #   Create the "release" commit:
 #     - CMakeLists.txt: Unset NVIM_VERSION_PRERELEASE
+#     - CMakeLists.txt: Unset NVIM_API_PRERELEASE
 #     - Tag the commit.
 #   Create the "version bump" commit:
 #     - CMakeLists.txt: Set NVIM_VERSION_PRERELEASE to "-dev"
@@ -46,6 +47,7 @@ __BUMP_MSG="version bump"
 echo "Most recent tag: ${__LAST_TAG}"
 echo "Release version: ${__VERSION}"
 $__sed -i.bk 's/(NVIM_VERSION_PRERELEASE) "-dev"/\1 ""/' CMakeLists.txt
+$__sed -i.bk 's/(NVIM_API_PRERELEASE) true/\1 false/' CMakeLists.txt
 echo "Building changelog since ${__LAST_TAG}..."
 __CHANGELOG="$(./scripts/git-log-pretty-since.sh "$__LAST_TAG" 'vim-patch:\S')"
 

src/nvim/api/private/helpers.c

@@ -18,6 +18,7 @@
 #include "nvim/map.h"
 #include "nvim/option.h"
 #include "nvim/option_defs.h"
+#include "nvim/version.h"
 #include "nvim/eval/typval_encode.h"
 #include "nvim/lib/kvec.h"
 
@@ -763,6 +764,7 @@ Dictionary api_metadata(void)
   static Dictionary metadata = ARRAY_DICT_INIT;
 
   if (!metadata.size) {
+    PUT(metadata, "version", DICTIONARY_OBJ(version_dict()));
     init_function_metadata(&metadata);
     init_error_type_metadata(&metadata);
     init_type_metadata(&metadata);

src/nvim/version.c

@@ -7,6 +7,7 @@
 #include <assert.h>
 #include <limits.h>
 
+#include "nvim/api/private/helpers.h"
 #include "nvim/vim.h"
 #include "nvim/ascii.h"
 #include "nvim/iconv.h"
@@ -2514,6 +2515,17 @@ bool has_vim_patch(int n)
   return false;
 }
 
+Dictionary version_dict(void) {
+  Dictionary d = ARRAY_DICT_INIT;
+  PUT(d, "major", INTEGER_OBJ(NVIM_VERSION_MAJOR));
+  PUT(d, "minor", INTEGER_OBJ(NVIM_VERSION_MINOR));
+  PUT(d, "patch", INTEGER_OBJ(NVIM_VERSION_PATCH));
+  PUT(d, "api_level", INTEGER_OBJ(NVIM_API_LEVEL));
+  PUT(d, "api_compatible", INTEGER_OBJ(NVIM_API_LEVEL_COMPAT));
+  PUT(d, "api_prerelease", BOOLEAN_OBJ(NVIM_API_PRERELEASE));
+  return d;
+}
+
 void ex_version(exarg_T *eap)
 {
   // Ignore a ":version 9.99" command.

test/functional/api/version_spec.lua

@@ -0,0 +1,71 @@
+local helpers = require('test.functional.helpers')(after_each)
+local mpack = require('mpack')
+local clear, funcs, eq = helpers.clear, helpers.funcs, helpers.eq
+
+local function read_mpack_file(fname)
+  local fd = io.open(fname, 'rb')
+  local data = fd:read('*a')
+  fd:close()
+  local unpack = mpack.Unpacker()
+  return unpack(data)
+end
+
+-- Remove metadata that is not essential to backwards-compatibility.
+local function remove_function_metadata(fspec)
+  fspec['can_fail'] = nil
+  fspec['async'] = nil
+  fspec['method'] = nil
+  fspec['since'] = nil
+  fspec['deprecated_since'] = nil
+  fspec['receives_channel_id'] = nil
+  for idx, _ in ipairs(fspec['parameters']) do
+    fspec['parameters'][idx][2] = ''  -- Remove parameter name.
+  end
+  return fspec
+end
+
+describe("api_info()['version']", function()
+  before_each(clear)
+
+  it("returns API level", function()
+    local version = helpers.call('api_info')['version']
+    local current = version['api_level']
+    local compat  = version['api_compatible']
+    eq("number", type(current))
+    eq("number", type(compat))
+    assert(current >= compat)
+  end)
+
+  it("returns Nvim version", function()
+    local version = helpers.call('api_info')['version']
+    local major   = version['major']
+    local minor   = version['minor']
+    local patch   = version['patch']
+    eq("number", type(major))
+    eq("number", type(minor))
+    eq("number", type(patch))
+    eq(1, funcs.has("nvim-"..major.."."..minor.."."..patch))
+    eq(0, funcs.has("nvim-"..major.."."..minor.."."..(patch + 1)))
+    eq(0, funcs.has("nvim-"..major.."."..(minor + 1).."."..patch))
+    eq(0, funcs.has("nvim-"..(major + 1).."."..minor.."."..patch))
+  end)
+
+  it("api_compatible level is valid", function()
+    local api     = helpers.call('api_info')
+    local compat  = api['version']['api_compatible']
+    local path    = 'test/functional/fixtures/api_level_'
+                    ..tostring(compat)..'.mpack'
+
+    -- Verify that the current API function signatures match those of the API
+    -- level for which we claim compatibility.
+    local old_api = read_mpack_file(path)
+    for _, fn_old in ipairs(old_api['functions']) do
+      for _, fn_new in ipairs(api['functions']) do
+        if fn_old['name'] == fn_new['name'] then
+          eq(remove_function_metadata(fn_old),
+             remove_function_metadata(fn_new))
+        end
+      end
+    end
+  end)
+end)

test/functional/eval/api_functions_spec.lua

@@ -106,7 +106,7 @@ describe('api functions', function()
 
   it('have metadata accessible with api_info()', function()
     local api_keys = eval("sort(keys(api_info()))")
-    eq({'error_types', 'functions', 'types'}, api_keys)
+    eq({'error_types', 'functions', 'types', 'version'}, api_keys)
   end)
 
   it('are highlighted by vim.vim syntax file', function()
@@ -144,5 +144,4 @@ describe('api functions', function()
     ]])
     screen:detach()
   end)
-
 end)

test/functional/eval/msgpack_functions_spec.lua

@@ -460,7 +460,7 @@ describe('msgpackparse() function', function()
     eval(cmd)
     eval(cmd)  -- do it again (try to force segfault)
     local api_info = eval(cmd)  -- do it again
-    eq({'error_types', 'functions', 'types'}, api_info)
+    eq({'error_types', 'functions', 'types', 'version'}, api_info)
   end)
 
   it('fails when called with no arguments', function()