fix relative path resolution

For .input.dscpath, a relative path is supposed to be relative to the
json file, but it was relative to cwd. For .output.directory, the matter
was unspecified, but should actually work in the same way. Adapt
implementation to documentation and fix the missing specification.

2 files changed, 14 insertions, 1 deletions

diff --git a/mdbp/build_schema.json b/mdbp/build_schema.json
index b8d905d..baa38ef 100644
--- a/mdbp/build_schema.json
+++ b/mdbp/build_schema.json
@@ -121,7 +121,7 @@
       "properties": {
         "directory": {
           "type": "string",
-          "description": "target directory to place output artifacts"
+          "description": "target directory to place output artifacts, can be specified relative to the location of this json file"
         }
       }
     }
diff --git a/mdbp/common.py b/mdbp/common.py
index d0d2f2d..77cbd33 100644
--- a/mdbp/common.py
+++ b/mdbp/common.py
@@ -37,6 +37,19 @@ def buildjson(filename: str) -> JsonObject:
             buildobj,
             json_load(
                 importlib.resources.open_text("mdbp", "build_schema.json")))
+    for attrs in (("input", "dscpath"), ("output", "directory")):
+        obj = buildobj
+        for attr in attrs[:-1]:
+            try:
+                obj = obj[attr]
+            except KeyError:
+                break
+        else:
+            try:
+                obj[attrs[-1]] = str(pathlib.Path(filename).parent /
+                                     pathlib.Path(obj[attrs[-1]]))
+            except KeyError:
+                pass
     assert isinstance(buildobj, dict)
     return buildobj