testing: Add a way to extract variables from the test suite

3 files changed, 43 insertions, 0 deletions

diff --git a/TESTING b/TESTING
index 6253086..8d65f15 100644
--- a/TESTING
+++ b/TESTING
@@ -254,3 +254,20 @@ Tip and tricks when writing tests for Gitano
   however, `bash` then you should take extra care not to write bashisms into
   your test implementations.
 
+Analysing the variables used in lace contexts
+=============================================
+
+The set of predicates and variables available to lace contexts
+depends on the operation, and in many cases the data in the repository.
+
+This makes it difficult to know exactly what variables are available.
+
+To aid with this, if `GITANO_DUMP_VARIABLE_FILE` is set in the environment
+it will write a table of variables and the operations they exist in
+to the file path in `GITANO_DUMP_VARIABLE_FILE`.
+
+To make use of this in the test suite add
+`--env GITANO_DUMP_VARIABLE_FILE=$file_path` to `YARN_ARGS`.
+
+This is not compatible with running yarns in parallel
+and depends on the test suite coverage to produce sufficient results.
diff --git a/lib/gitano/repository.lua b/lib/gitano/repository.lua
index 7858a33..e48267f 100644
--- a/lib/gitano/repository.lua
+++ b/lib/gitano/repository.lua
@@ -165,6 +165,29 @@ end
 function repo_method:run_lace(context)
    self:populate_context(context)
    config.populate_context(self.config, context)
+   local vardump = luxio.getenv("GITANO_DUMP_VARIABLE_FILE")
+   if vardump then
+      local io = require "io"
+      local pretty = require "pl.pretty"
+      local t
+      local fh = io.open(vardump, "r")
+      if not fh then
+         t = {}
+      else
+         t = pretty.read(fh:read("*a"))
+         fh:close()
+      end
+      local op = context.operation
+      for k, _ in pairs(context) do
+         if not t[k] then
+            t[k] = {}
+         end
+         t[k][op] = true
+      end
+      local fh = io.open(vardump, "w+")
+      fh:write(pretty.write(t))
+      fh:close()
+   end
    return lace.run(self.lace, context)
 end
 
diff --git a/testing/gitano-test-tool.in b/testing/gitano-test-tool.in
index 88ccbc5..944a3c2 100644
--- a/testing/gitano-test-tool.in
+++ b/testing/gitano-test-tool.in
@@ -46,6 +46,9 @@ local function unix_assert(ret, errno)
 end
 
 local function run_program(t)
+   if t.env and os.getenv("GITANO_DUMP_VARIABLE_FILE") then
+      t.env["GITANO_DUMP_VARIABLE_FILE"] = os.getenv("GITANO_DUMP_VARIABLE_FILE")
+   end
    local f = io.open(basedir .. "last-program", "w")
    local function print (...)
       f:write(...)