Fix issues with infered_from and add checks for infered_from and depends_on that are strings

.travis.yml

@@ -41,12 +41,14 @@ script:
     - |
       pip uninstall -y qcodes
       pip install -e .
-      cd qcodes/tests/dataset/legacy_DB_generation
+      cd ..
+      git clone https://github.com/QCoDeS/qcodes_generate_test_db.git
+      cd qcodes_generate_test_db
       python generate_version_0.py
       python generate_version_1.py
       python generate_version_2.py
       python generate_version_3.py
-      cd ../../../..
+      cd $TRAVIS_BUILD_DIR
       pip uninstall -y qcodes
       pip install .
     - cd qcodes

azure-pipelines.yml

@@ -29,11 +29,13 @@ jobs:
           mypy qcodes
         displayName: "mypy"
       - script: |
-          cd qcodes
-          python tests\dataset\legacy_DB_generation\generate_version_0.py
-          python tests\dataset\legacy_DB_generation\generate_version_1.py
-          python tests\dataset\legacy_DB_generation\generate_version_2.py
-          python tests\dataset\legacy_DB_generation\generate_version_3.py
+          cd ..
+          git clone https://github.com/QCoDeS/qcodes_generate_test_db.git
+          cd qcodes_generate_test_db
+          python generate_version_0.py
+          python generate_version_1.py
+          python generate_version_2.py
+          python generate_version_3.py
         displayName: "Generate db fixtures"
       - script: |
           cd qcodes

qcodes/dataset/param_spec.py

@@ -45,15 +45,16 @@ def __init__(self, name: str,
 
         if isinstance(inferred_from, str):
             raise ValueError(f"ParamSpec {self.name} got "
-                             f"string {inferred_from} it needs a "
+                             f"string {inferred_from} as inferred_from. "
+                             f"It needs a "
                              f"Sequence of ParamSpecs or strings")
         self._inferred_from.extend(
             p.name if isinstance(p, ParamSpec) else p
             for p in inferred_from)
 
         if isinstance(depends_on, str):
             raise ValueError(f"ParamSpec {self.name} got "
-                             f"string {depends_on} it needs a "
+                             f"string {depends_on} as depends_on. It needs a "
                              f"Sequence of ParamSpecs or strings")
         self._depends_on.extend(
             p.name if isinstance(p, ParamSpec) else p

qcodes/dataset/sqlite_base.py

@@ -615,37 +615,23 @@ def _2to3_get_paramspecs(conn: ConnectionPlus,
                 paramtype = row['type']
                 break
 
-        # first possibility: another parameter depends on this parameter
-        if layout_id in indeps:
-            inferred_from_list = inferred_from.split(', ')
-
-            paramspec = ParamSpec(name=name, paramtype=paramtype,
-                                  label=label, unit=unit,
-                                  inferred_from=inferred_from_list)
-            paramspecs[layout_id] = paramspec
-
-        # second possibility: this parameter depends on another parameter
-        elif layout_id in deps:
+        inferred_from_list: List[str] = []
+        depends_on: List[str] = []
 
+        # this parameter depends on another parameter
+        if layout_id in deps:
             setpoints = dependencies[layout_id]
             depends_on = [paramspecs[idp].name for idp in setpoints]
-            inferred_from_list = inferred_from.split(', ')
 
-            paramspec = ParamSpec(name=name,
-                                  paramtype=paramtype,
-                                  label=label, unit=unit,
-                                  depends_on=depends_on,
-                                  inferred_from=inferred_from_list)
-            paramspecs[layout_id] = paramspec
+        if inferred_from != '':
+            inferred_from_list = inferred_from.split(', ')
 
-        # third possibility: no dependencies
-        else:
-            paramspec = ParamSpec(name=name,
-                                  paramtype=paramtype,
-                                  label=label, unit=unit,
-                                  depends_on=[],
-                                  inferred_from=[])
-            paramspecs[layout_id] = paramspec
+        paramspec = ParamSpec(name=name,
+                              paramtype=paramtype,
+                              label=label, unit=unit,
+                              depends_on=depends_on,
+                              inferred_from=inferred_from_list)
+        paramspecs[layout_id] = paramspec
 
     return paramspecs
 
@@ -727,7 +713,7 @@ def perform_db_upgrade_2_to_3(conn: ConnectionPlus) -> None:
 def perform_db_upgrade_3_to_4(conn: ConnectionPlus) -> None:
     """
     Perform the upgrade from version 3 to version 4. This really
-    repeats the version 3 upgrade as it originally had a bug in
+    repeats the version 3 upgrade as it originally had two bugs in
     the inferred annotation. This has since been fixes so rerun
     the upgrade.
     """