feat: add "wizard" for creating new table/model/revision

pyproject.toml

@@ -42,6 +42,7 @@ dependencies = [
         "pyramid_fanstatic",
         "pyramid_mako",
         "pyramid_tm",
+        "SQLAlchemy-Utils",
         "waitress",
         "WebHelpers2",
         "WuttJamaican[db]>=0.27.0",

src/wuttaweb/code-templates/new-table.mako

@@ -0,0 +1,68 @@
+## -*- coding: utf-8; mode: python; -*-
+# -*- coding: utf-8; -*-
+"""
+Model definition for ${model_title_plural}
+"""
+
+import sqlalchemy as sa
+from sqlalchemy import orm
+
+from wuttjamaican.db import model
+
+
+class ${model_name}(model.Base):
+    """
+    ${description}
+    """
+    __tablename__ = "${table_name}"
+    % if any([c["data_type"]["type"] == "_fk_uuid_" for c in columns]):
+    __table_args__ = (
+        % for column in columns:
+        % if column["data_type"]["type"] == "_fk_uuid_":
+        sa.ForeignKeyConstraint(["${column['name']}"], ["${column['data_type']['reference']}.uuid"],
+                                name="${table_name}_fk_${column['data_type']['reference']}"),
+        % endif
+        % endfor
+    )
+    % endif
+    % if versioned:
+    % if all([c["versioned"] for c in columns]):
+    __versioned__ = {}
+    % else:
+    __versioned__ = {
+        "exclude": [
+            % for column in columns:
+            % if not column["versioned"]:
+            "${column['name']}",
+            % endif
+            % endfor
+        ],
+    }
+    % endif
+    % endif
+    __wutta_hint__ = {
+        "model_title": "${model_title}",
+        "model_title_plural": "${model_title_plural}",
+    }
+    % for column in columns:
+
+    % if column["name"] == "uuid":
+    uuid = model.uuid_column()
+    % else:
+    ${column["name"]} = sa.Column(${column["formatted_data_type"]}, nullable=${column["nullable"]}, doc="""
+    ${column["description"] or ""}
+    """)
+    % if column["data_type"]["type"] == "_fk_uuid_" and column["relationship"]:
+    ${column["relationship"]["name"]} = orm.relationship(
+        "${column['relationship']['reference_model']}",
+        doc="""
+        ${column["description"] or ""}
+        """)
+    % endif
+    % endif
+    % endfor
+
+    # TODO: you usually should define the __str__() method
+
+    # def __str__(self):
+    #     return self.name or ""

src/wuttaweb/templates/alembic/dashboard.mako

@@ -27,11 +27,18 @@
 
     <div>
       <div class="buttons">
-        % if request.has_perm("tables.list"):
+        % if request.has_perm("app_tables.list"):
             <wutta-button type="is-primary"
-                          tag="a" href="${url('tables')}"
+                          tag="a" href="${url('app_tables')}"
                           icon-left="table"
-                          label="Database Tables"
+                          label="App Tables"
+                          once />
+        % endif
+        % if request.has_perm("app_tables.create"):
+            <wutta-button type="is-primary"
+                          tag="a" href="${url('app_tables.create')}"
+                          icon-left="plus"
+                          label="New Table"
                           once />
         % endif
       </div>

src/wuttaweb/templates/alembic/migrations/index.mako

@@ -12,11 +12,11 @@
                       once />
     % endif
 
-    % if request.has_perm("tables.list"):
+    % if request.has_perm("app_tables.list"):
         <wutta-button type="is-primary"
-                      tag="a" href="${url('tables')}"
+                      tag="a" href="${url('app_tables')}"
                       icon-left="table"
-                      label="Database Tables"
+                      label="App Tables"
                       once />
     % endif
 

src/wuttaweb/templates/appinfo/index.mako

@@ -34,11 +34,11 @@
 
   <div class="buttons">
 
-    % if request.has_perm("tables.list"):
+    % if request.has_perm("app_tables.list"):
         <wutta-button type="is-primary"
-                      tag="a" href="${url('tables')}"
+                      tag="a" href="${url('app_tables')}"
                       icon-left="table"
-                      label="Database Tables"
+                      label="App Tables"
                       once />
     % endif
 

src/wuttaweb/views/alembic.py

@@ -443,14 +443,18 @@ class AlembicMigrationView(MasterView):  # pylint: disable=abstract-method
 
         return form
 
-    def validate_revise_branch(self, node, value):
+    def validate_revise_branch(  # pylint: disable=missing-function-docstring
+        self, node, value
+    ):
         if value["branching_option"] == "revise":
             if not value["revise_branch"]:
                 node["revise_branch"].raise_invalid(
                     "Must specify which branch to revise."
                 )
 
-    def validate_new_branch(self, node, value):
+    def validate_new_branch(  # pylint: disable=missing-function-docstring
+        self, node, value
+    ):
         if value["branching_option"] == "new":
 
             if not value["new_branch"]:
@@ -464,7 +468,6 @@ class AlembicMigrationView(MasterView):  # pylint: disable=abstract-method
     def save_create_form(self, form):  # pylint: disable=empty-docstring
         """ """
         alembic = make_alembic_config(self.config)
-        script = get_alembic_scriptdir(self.config, alembic)
         data = form.validated
 
         # kwargs for `alembic revision` command
@@ -486,7 +489,8 @@ class AlembicMigrationView(MasterView):  # pylint: disable=abstract-method
         intro = HTML.tag(
             "p",
             class_="block",
-            c="New migration script has been created.  Please review and modify the file contents as needed:",
+            c="New migration script has been created.  "
+            "Please review and modify the file contents as needed:",
         )
 
         path = HTML.tag(
@@ -516,7 +520,10 @@ class AlembicMigrationView(MasterView):  # pylint: disable=abstract-method
         rev = self.get_instance()
         os.remove(rev["path"])
 
-    def get_revise_branch_options(self, script):
+    # TODO: this is effectivey duplicated in AppTableView.get_migration_branch_options()
+    def get_revise_branch_options(  # pylint: disable=missing-function-docstring
+        self, script
+    ):
         branches = set()
         for rev in script.get_revisions(script.get_heads()):
             branches.update(rev.branch_labels)

src/wuttaweb/views/tables.py

@@ -24,12 +24,23 @@
 Table Views
 """
 
-import sqlalchemy as sa
+import os
+
+from alembic import command as alembic_command
+from sqlalchemy_utils import get_mapper
+from mako.lookup import TemplateLookup
+from webhelpers2.html import HTML
+
+from wuttjamaican.db.conf import (
+    check_alembic_current,
+    make_alembic_config,
+    get_alembic_scriptdir,
+)
 
 from wuttaweb.views import MasterView
 
 
-class TableView(MasterView):
+class AppTableView(MasterView):  # pylint: disable=abstract-method
     """
     Master view showing all tables in the :term:`app database`.
 
@@ -40,17 +51,20 @@ class TableView(MasterView):
     * ``/tables/``
     """
 
-    model_name = "table"
+    # pylint: disable=duplicate-code
-    model_title = "Database Table"
+    model_name = "app_table"
+    model_title = "App Table"
     model_key = "name"
+    url_prefix = "/tables/app"
     filterable = False
     sortable = True
     sort_on_backend = False
     paginated = True
     paginate_on_backend = False
-    creatable = False
+    creatable = True
     editable = False
     deletable = False
+    # pylint: enable=duplicate-code
 
     labels = {
         "name": "Table Name",
@@ -70,6 +84,23 @@ class TableView(MasterView):
         # "row_count",
     ]
 
+    has_rows = True
+    rows_title = "Columns"
+    rows_filterable = False
+    rows_sort_defaults = "sequence"
+    rows_sort_on_backend = False
+    rows_paginated = True
+    rows_paginate_on_backend = False
+    rows_viewable = False
+
+    row_grid_columns = [
+        "sequence",
+        "column_name",
+        "data_type",
+        "nullable",
+        "description",
+    ]
+
     def get_grid_data(  # pylint: disable=empty-docstring
         self, columns=None, session=None
     ):
@@ -93,6 +124,9 @@ class TableView(MasterView):
         g = grid
         super().configure_grid(g)
 
+        # nb. show more tables by default
+        g.pagesize = 50
+
         # schema
         g.set_searchable("schema")
 
@@ -100,7 +134,9 @@ class TableView(MasterView):
         g.set_searchable("name")
         g.set_link("name")
 
-    def get_instance(self):  # pylint: disable=empty-docstring
+    def get_instance(  # pylint: disable=empty-docstring,arguments-differ,unused-argument
+        self, **kwargs
+    ):
         """ """
         if "_cached_instance" not in self.__dict__:
             model = self.app.model
@@ -111,6 +147,7 @@ class TableView(MasterView):
                 "name": table.name,
                 "schema": table.schema or "",
                 # "row_count": 42,
+                "table": table,
             }
 
             self.__dict__["_cached_instance"] = data
@@ -121,14 +158,248 @@ class TableView(MasterView):
         """ """
         return instance["name"]
 
+    def get_row_grid_data(self, obj):  # pylint: disable=empty-docstring
+        """ """
+        table = obj
+        data = []
+        for i, column in enumerate(table["table"].columns, 1):
+            data.append(
+                {
+                    "column": column,
+                    "sequence": i,
+                    "column_name": column.name,
+                    "data_type": str(repr(column.type)),
+                    "nullable": column.nullable,
+                    "description": (column.doc or "").strip(),
+                }
+            )
+        return data
+
+    def configure_row_grid(self, grid):  # pylint: disable=empty-docstring
+        """ """
+        g = grid
+        super().configure_row_grid(g)
+
+        # nb. try not to hide any columns by default
+        g.pagesize = 100
+
+        # sequence
+        g.set_label("sequence", "Seq.")
+
+        # column_name
+        g.set_searchable("column_name")
+
+        # data_type
+        g.set_searchable("data_type")
+
+        # nullable
+        g.set_renderer("nullable", "boolean")
+
+        # description
+        g.set_searchable("description")
+        g.set_renderer("description", self.render_column_description)
+
+    def render_column_description(  # pylint: disable=missing-function-docstring,unused-argument
+        self, column, field, value
+    ):
+        if not value:
+            return ""
+
+        max_length = 100
+        if len(value) <= max_length:
+            return value
+
+        return HTML.tag("span", title=value, c=f"{value[:max_length]} ...")
+
+    def get_template_context(self, context):  # pylint: disable=empty-docstring
+        """ """
+        if self.creating:
+            model = self.app.model
+
+            # alembic current
+            context["alembic_is_current"] = check_alembic_current(self.config)
+
+            # existing tables
+            # TODO: any reason this should check grid data instead of metadata?
+            unwanted = ["transaction", "transaction_meta"]
+            context["existing_tables"] = [
+                {"name": table}
+                for table in sorted(model.Base.metadata.tables)
+                if table not in unwanted and not table.endswith("_version")
+            ]
+
+            # model dir
+            context["model_dir"] = os.path.dirname(model.__file__)
+
+            # migration branch
+            script = get_alembic_scriptdir(self.config)
+            branch_options = self.get_migration_branch_options(script)
+            context["migration_branch_options"] = branch_options
+            branch = self.config.get(
+                f"{self.config.appname}.alembic.default_revise_branch"
+            )
+            if not branch and len(branch_options) == 1:
+                branch = branch_options[0]
+            context["migration_branch"] = branch
+
+        return context
+
+    # TODO: this is effectivey duplicated in AlembicMigrationView.get_revise_branch_options()
+    def get_migration_branch_options(  # pylint: disable=missing-function-docstring
+        self, script
+    ):
+        branches = set()
+        for rev in script.get_revisions(script.get_heads()):
+            branches.update(rev.branch_labels)
+        return sorted(branches)
+
+    def wizard_action(self):  # pylint: disable=too-many-return-statements
+        """
+        AJAX view to handle various actions for the "new table" wizard.
+        """
+        data = self.request.json_body
+        action = data.get("action", "").strip()
+        try:
+
+            # nb. cannot use match/case statement until python 3.10, but this
+            # project technically still supports python 3.8
+            if action == "write_model_file":
+                return self.write_model_file(data)
+            if action == "check_model":
+                return self.check_model(data)
+            if action == "write_revision_script":
+                return self.write_revision_script(data)
+            if action == "migrate_db":
+                return self.migrate_db(data)
+            if action == "check_table":
+                return self.check_table(data)
+            if action == "":
+                return {"error": "Must specify the action to perform."}
+            return {"error": f"Unknown action requested: {action}"}
+
+        except Exception as err:  # pylint: disable=broad-exception-caught
+            return {"error": f"Unexpected error occurred: {err}"}
+
+    def write_model_file(self, data):  # pylint: disable=missing-function-docstring
+        model = self.app.model
+        path = data["module_file"]
+
+        if os.path.exists(path):
+            if data["overwrite"]:
+                os.remove(path)
+            else:
+                return {"error": "File already exists"}
+
+        for column in data["columns"]:
+            if column["data_type"]["type"] == "_fk_uuid_" and column["relationship"]:
+                name = column["relationship"]
+
+                table = model.Base.metadata.tables[column["data_type"]["reference"]]
+                mapper = get_mapper(table)
+                reference_model = mapper.class_.__name__
+
+                column["relationship"] = {
+                    "name": name,
+                    "reference_model": reference_model,
+                }
+
+        # TODO: make templates dir configurable?
+        templates = [self.app.resource_path("wuttaweb:code-templates")]
+        table_templates = TemplateLookup(directories=templates)
+
+        template = table_templates.get_template("/new-table.mako")
+        content = template.render(**data)
+        with open(path, "wt", encoding="utf_8") as f:
+            f.write(content)
+
+        return {}
+
+    def check_model(self, data):  # pylint: disable=missing-function-docstring
+        model = self.app.model
+        model_name = data["model_name"]
+
+        if not hasattr(model, model_name):
+            return {
+                "problem": "class not found in app model",
+                "model": model.__name__,
+            }
+
+        return {}
+
+    def write_revision_script(self, data):  # pylint: disable=missing-function-docstring
+        alembic_config = make_alembic_config(self.config)
+
+        script = alembic_command.revision(
+            alembic_config,
+            autogenerate=True,
+            head=f"{data['branch']}@head",
+            message=data["message"],
+        )
+
+        return {"script": script.path}
+
+    def migrate_db(  # pylint: disable=missing-function-docstring,unused-argument
+        self, data
+    ):
+        alembic_config = make_alembic_config(self.config)
+        alembic_command.upgrade(alembic_config, "heads")
+        return {}
+
+    def check_table(self, data):  # pylint: disable=missing-function-docstring
+        model = self.app.model
+        name = data["name"]
+
+        table = model.Base.metadata.tables.get(name)
+        if table is None:
+            return {"problem": "table does not exist in app model"}
+
+        session = self.Session()
+        count = session.query(table).count()
+
+        route_prefix = self.get_route_prefix()
+        url = self.request.route_url(f"{route_prefix}.view", name=name)
+        return {"url": url, "count": count}
+
+    @classmethod
+    def defaults(cls, config):  # pylint: disable=empty-docstring
+        """ """
+        cls._apptable_defaults(config)
+        cls._defaults(config)
+
+    @classmethod
+    def _apptable_defaults(cls, config):
+        route_prefix = cls.get_route_prefix()
+        permission_prefix = cls.get_permission_prefix()
+        model_title_plural = cls.get_model_title_plural()
+        url_prefix = cls.get_url_prefix()
+
+        # fix permission group
+        config.add_wutta_permission_group(
+            permission_prefix, model_title_plural, overwrite=False
+        )
+
+        # wizard actions
+        config.add_route(
+            f"{route_prefix}.wizard_action",
+            f"{url_prefix}/new/wizard-action",
+            request_method="POST",
+        )
+        config.add_view(
+            cls,
+            attr="wizard_action",
+            route_name=f"{route_prefix}.wizard_action",
+            renderer="json",
+            permission=f"{permission_prefix}.create",
+        )
+
 
 def defaults(config, **kwargs):  # pylint: disable=missing-function-docstring
     base = globals()
 
-    TableView = kwargs.get(  # pylint: disable=invalid-name,redefined-outer-name
+    AppTableView = kwargs.get(  # pylint: disable=invalid-name,redefined-outer-name
-        "TableView", base["TableView"]
+        "AppTableView", base["AppTableView"]
     )
-    TableView.defaults(config)
+    AppTableView.defaults(config)
 
 
 def includeme(config):  # pylint: disable=missing-function-docstring

tests/views/test_tables.py

@@ -1,15 +1,38 @@
 # -*- coding: utf-8; -*-
 
+import os
 from unittest.mock import patch
 
+from alembic import command as alembic_command
+
+from wuttjamaican.db.conf import check_alembic_current, make_alembic_config
+
 from wuttaweb.testing import WebTestCase
 from wuttaweb.views import tables as mod
 
 
-class TestUpgradeView(WebTestCase):
+class TestAppTableView(WebTestCase):
+
+    def make_config(self, **kwargs):
+        sqlite_path = self.write_file("test.sqlite", "")
+        self.sqlite_engine_url = f"sqlite:///{sqlite_path}"
+
+        config_path = self.write_file(
+            "test.ini",
+            f"""
+[wutta.db]
+default.url = {self.sqlite_engine_url}
+
+[alembic]
+script_location = wuttjamaican.db:alembic
+version_locations = wuttjamaican.db:alembic/versions
+""",
+        )
+
+        return super().make_config([config_path], **kwargs)
 
     def make_view(self):
-        return mod.TableView(self.request)
+        return mod.AppTableView(self.request)
 
     def test_includeme(self):
         self.pyramid_config.include("wuttaweb.views.tables")
@@ -51,3 +74,253 @@ class TestUpgradeView(WebTestCase):
 
         table = {"name": "poser_foo"}
         self.assertEqual(view.get_instance_title(table), "poser_foo")
+
+    def test_get_row_grid_data(self):
+        model = self.app.model
+        view = self.make_view()
+
+        table = model.Base.metadata.tables["person"]
+        table_dict = {"name": "person", "table": table}
+
+        data = view.get_row_grid_data(table_dict)
+        self.assertIsInstance(data, list)
+        self.assertGreater(len(data), 4)
+        columns = [c["column_name"] for c in data]
+        self.assertIn("full_name", columns)
+        self.assertIn("first_name", columns)
+        self.assertIn("last_name", columns)
+
+    def test_configure_row_grid(self):
+        view = self.make_view()
+
+        # sanity / coverage check
+        grid = view.make_grid(columns=["column_name", "data_type"])
+        view.configure_row_grid(grid)
+
+    def test_render_column_description(self):
+        view = self.make_view()
+
+        # nb. first 2 params are igored
+        text = view.render_column_description(None, None, "hello world")
+        self.assertEqual(text, "hello world")
+
+        text = view.render_column_description(None, None, "")
+        self.assertEqual(text, "")
+        text = view.render_column_description(None, None, None)
+        self.assertEqual(text, "")
+
+        msg = (
+            "This is a very long and rambling sentence.  "
+            "There is no point to it except that it is long.  "
+            "Far too long to be reasonable."
+            "I mean I am serious when I say this is simply too long."
+        )
+        text = view.render_column_description(None, None, msg)
+        self.assertNotEqual(text, msg)
+        self.assertIn("<span title=", text)
+
+    def test_get_template_context(self):
+        view = self.make_view()
+
+        # normal view gets no extra context
+        context = view.get_template_context({})
+        self.assertIsInstance(context, dict)
+        self.assertNotIn("alembic_is_current", context)
+        self.assertNotIn("existing_tables", context)
+        self.assertNotIn("model_dir", context)
+        self.assertNotIn("migration_branch_options", context)
+        self.assertNotIn("migration_branch", context)
+
+        # but 'create' view gets extra context
+        with patch.object(view, "creating", new=True):
+            context = view.get_template_context({})
+            self.assertIsInstance(context, dict)
+            self.assertIn("alembic_is_current", context)
+            self.assertIn("existing_tables", context)
+            self.assertIn("model_dir", context)
+            self.assertIn("migration_branch_options", context)
+            self.assertIn("migration_branch", context)
+
+    def test_write_model_file(self):
+        view = self.make_view()
+        module_path = self.write_file("widget.py", "")
+        self.assertEqual(os.path.getsize(module_path), 0)
+
+        sample = {
+            "action": "write_model_file",
+            "module_file": module_path,
+            "overwrite": False,
+            "table_name": "poser_widget",
+            "model_name": "PoserWidget",
+            "model_title": "Poser Widget",
+            "model_title_plural": "Poser Widgets",
+            "description": "A widget for Poser",
+            "versioned": True,
+            "columns": [
+                {
+                    "name": "uuid",
+                    "data_type": {
+                        "type": "UUID",
+                    },
+                    "formatted_data_type": "sa.UUID()",
+                    "nullable": False,
+                    "description": "primary key",
+                    "versioned": "n/a",
+                    "relationship": None,
+                },
+                {
+                    "name": "name",
+                    "data_type": {
+                        "type": "String",
+                    },
+                    "formatted_data_type": "sa.String(length=100)",
+                    "nullable": False,
+                    "description": "name of widget",
+                    "versioned": True,
+                    "relationship": None,
+                },
+                {
+                    "name": "owner_uuid",
+                    "data_type": {
+                        "type": "_fk_uuid_",
+                        "reference": "user",
+                    },
+                    "formatted_data_type": "sa.UUID()",
+                    "nullable": False,
+                    "description": "owner of widget",
+                    "versioned": True,
+                    "relationship": {
+                        "name": "owner",
+                        "reference_model": "User",
+                    },
+                },
+            ],
+        }
+
+        with patch.object(self.request, "json_body", new=sample, create=True):
+
+            # does not overwrite by default
+            result = view.wizard_action()
+            self.assertIn("error", result)
+            self.assertEqual(result["error"], "File already exists")
+
+            # but it can overwrite if requested
+            with patch.dict(sample, {"overwrite": True}):
+                result = view.wizard_action()
+                self.assertNotIn("error", result)
+                self.assertGreater(os.path.getsize(module_path), 1000)
+
+    def test_check_model(self):
+        view = self.make_view()
+        sample = {
+            "action": "check_model",
+            "model_name": "Person",
+        }
+
+        with patch.object(self.request, "json_body", new=sample, create=True):
+
+            # empty result means the model exists
+            result = view.wizard_action()
+            self.assertEqual(result, {})
+
+            # problem is specified if not
+            with patch.dict(sample, {"model_name": "gobbledygook"}):
+                result = view.wizard_action()
+                self.assertIn("problem", result)
+                self.assertEqual(result["problem"], "class not found in app model")
+
+    def test_write_revision_script(self):
+        view = self.make_view()
+        sample = {
+            "action": "write_revision_script",
+            "branch": "wutta",
+            "message": "just a test",
+        }
+
+        # tell alembic our db is already current
+        alembic = make_alembic_config(self.config)
+        alembic_command.stamp(alembic, "heads")
+        self.assertTrue(check_alembic_current(self.config, alembic))
+
+        with patch.object(self.request, "json_body", new=sample, create=True):
+
+            # nb. this writes a real script in the wuttjamaican project
+            result = view.wizard_action()
+            self.assertIn("script", result)
+            outdir = os.path.dirname(result["script"])
+            self.assertEqual(
+                outdir, self.app.resource_path("wuttjamaican.db:alembic/versions")
+            )
+
+            # alembic now thinks we need to upgrade
+            self.assertFalse(check_alembic_current(self.config, alembic))
+
+            # must be sure to delete that script
+            os.remove(result["script"])
+
+    def test_migrate_db(self):
+        view = self.make_view()
+        sample = {"action": "migrate_db"}
+
+        # tell alembic our db is already current
+        alembic = make_alembic_config(self.config)
+        alembic_command.stamp(alembic, "heads")
+        self.assertTrue(check_alembic_current(self.config, alembic))
+
+        # force downgrade to wutta@-1
+        alembic_command.downgrade(alembic, "wutta@-1")
+
+        # alembic now thinks we need to upgrade
+        self.assertFalse(check_alembic_current(self.config, alembic))
+
+        with patch.object(self.request, "json_body", new=sample, create=True):
+
+            # now test our view method; alembic should then know we are current
+            view.wizard_action()
+            self.assertTrue(check_alembic_current(self.config, alembic))
+
+    def test_check_table(self):
+        self.pyramid_config.add_route("app_tables.view", "/tables/app/{name}")
+        view = self.make_view()
+        sample = {"action": "check_table", "name": "person"}
+
+        with patch.object(view, "Session", return_value=self.session):
+
+            with patch.object(self.request, "json_body", new=sample, create=True):
+
+                # result with URL means the table exists
+                result = view.wizard_action()
+                self.assertIn("url", result)
+                self.assertNotIn("problem", result)
+
+                # problem is specified if not
+                with patch.dict(sample, {"name": "gobbledygook"}):
+                    result = view.wizard_action()
+                self.assertIn("problem", result)
+                self.assertEqual(result["problem"], "table does not exist in app model")
+
+    def test_wizard_action(self):
+        view = self.make_view()
+
+        # missing action
+        with patch.object(self.request, "json_body", create=True, new={}):
+            result = view.wizard_action()
+            self.assertIn("error", result)
+            self.assertEqual(result["error"], "Must specify the action to perform.")
+
+        # unknown action
+        with patch.object(
+            self.request, "json_body", create=True, new={"action": "nothing"}
+        ):
+            result = view.wizard_action()
+            self.assertIn("error", result)
+            self.assertEqual(result["error"], "Unknown action requested: nothing")
+
+        # error invoking action
+        with patch.object(
+            self.request, "json_body", create=True, new={"action": "check_table"}
+        ):
+            with patch.object(view, "check_table", side_effect=RuntimeError("whoa")):
+                result = view.wizard_action()
+                self.assertIn("error", result)
+                self.assertEqual(result["error"], "Unexpected error occurred: whoa")