Feature: Block-level copying of Jinja content between split projects

dbt_meshify/change.py

@@ -9,6 +9,7 @@ class Operation(str, Enum):
     """An operation describes the type of work being performed."""
 
     Add = "add"
+    Append = "append"
     Update = "update"
     Remove = "remove"
     Copy = "copy"
@@ -17,6 +18,7 @@ class Operation(str, Enum):
 
 prepositions = {
     Operation.Add: "to",
+    Operation.Append: "to",
     Operation.Move: "to",
     Operation.Copy: "to",
     Operation.Update: "in",

dbt_meshify/dbt_projects.py

@@ -26,6 +26,7 @@
 
 from dbt_meshify.dbt import Dbt
 from dbt_meshify.exceptions import FatalMeshifyException
+from dbt_meshify.storage.jinja_blocks import JinjaBlock, find_doc_reference
 
 
 class BaseDbtProject:
@@ -310,6 +311,30 @@ def __init__(
         resources = self.select_resources(output_key="unique_id")
 
         super().__init__(manifest, project, catalog, name, resources)
+        self.jinja_blocks: Dict[str, JinjaBlock] = self.find_jinja_blocks()
+
+    def find_jinja_blocks(self) -> Dict[str, JinjaBlock]:
+        """For a given dbt Project, find all Jinja blocks for docs and macros"""
+
+        blocks = {}
+
+        for unique_id, item in self.manifest.docs.items():
+            if item.package_name != self.name:
+                continue
+
+            blocks[unique_id] = JinjaBlock.from_file(
+                path=self.path / item.original_file_path, block_type="docs", name=item.name
+            )
+
+        for unique_id, macro in self.manifest.macros.items():
+            if macro.package_name != self.name:
+                continue
+
+            blocks[unique_id] = JinjaBlock.from_file(
+                path=self.path / macro.original_file_path, block_type="macro", name=macro.name
+            )
+
+        return blocks
 
     def select_resources(
         self,
@@ -396,6 +421,8 @@ def __init__(
         self.groups = self._get_indirect_groups()
         self._rename_project()
 
+        self._referenced_docs: Optional[Set[str]] = None
+
     def _rename_project(self) -> None:
         """
         edits the project yml to take any instance of the parent project name and update it to the subproject name
@@ -432,6 +459,39 @@ def _get_custom_macros(self) -> Set[str]:
                 macros_set.update(self._get_macro_dependencies(macro))
         return macros_set
 
+    @property
+    def referenced_docs(self) -> Set[str]:
+        """Return a list of all docs referenced within this SubProject."""
+
+        if self._referenced_docs:
+            return self._referenced_docs
+
+        docs = set()
+        for unique_id in self.resources:
+            if unique_id.startswith("test."):
+                continue
+
+            node = self.get_manifest_node(unique_id)
+
+            if node is None:
+                raise Exception(f"Unable to find referenced node {node}")
+
+            if hasattr(node, "raw_code"):
+                docs.update(find_doc_reference(node.raw_code))
+
+            if hasattr(node, "patch_path"):
+                path = self.parent_project.resolve_patch_path(node)
+                if path.exists():
+                    with open(path) as file:
+                        docs.update(find_doc_reference(file.read()))
+
+        # Use the search name for the doc to resolve a unique_id for the doc resource.
+        self._referenced_docs = {
+            unique_id for unique_id, doc in self.manifest.docs.items() if doc.name in docs
+        }
+
+        return self._referenced_docs
+
     def _get_indirect_groups(self) -> Set[str]:
         """
         get a set of group unique_ids for all the selected resources

dbt_meshify/main.py

@@ -246,7 +246,8 @@ def split(
         change_set = subproject_creator.initialize()
 
         return [change_set]
-    except Exception:
+    except Exception as e:
+        logger.exception(e)  # TODO: Remove this line!
         raise FatalMeshifyException(f"Error creating subproject {subproject.name}")
 
 

dbt_meshify/storage/dbt_project_editors.py

@@ -22,6 +22,7 @@
 from dbt_meshify.dbt_projects import DbtSubProject
 from dbt_meshify.storage.file_content_editors import NamedList, filter_empty_dict_items
 from dbt_meshify.storage.file_manager import YAMLFileManager, yaml
+from dbt_meshify.storage.jinja_blocks import JinjaBlock
 from dbt_meshify.utilities.contractor import Contractor
 from dbt_meshify.utilities.dependencies import DependenciesUpdater
 from dbt_meshify.utilities.grouper import ResourceGrouper
@@ -141,7 +142,12 @@ def initialize(self) -> ChangeSet:
             f"Identifying operations required to split {subproject.name} from {subproject.parent_project.name}."
         )
 
-        for unique_id in subproject.resources | subproject.custom_macros | subproject.groups:
+        for unique_id in (
+            subproject.resources
+            | subproject.custom_macros
+            | subproject.groups
+            | subproject.referenced_docs
+        ):
             resource = subproject.get_manifest_node(unique_id)
             if not resource:
                 raise KeyError(f"Resource {unique_id} not found in manifest")
@@ -182,10 +188,20 @@ def initialize(self) -> ChangeSet:
                 ):
                     change_set.extend(reference_updater.update_parent_refs(resource))
 
-            elif resource.resource_type in ["macro", "group"]:
+            elif resource.resource_type in ["macro", "group", "doc"]:
                 if hasattr(resource, "patch_path") and resource.patch_path:
                     change_set.add(self.copy_resource_yml(resource))
-                change_set.add(self.copy_resource(resource))
+
+                if resource.unique_id in self.subproject.parent_project.jinja_blocks:
+                    change_set.add(
+                        self.copy_jinja_block(
+                            resource,
+                            self.subproject.parent_project.jinja_blocks[resource.unique_id],
+                        )
+                    )
+
+                else:
+                    change_set.add(self.copy_resource(resource))
 
             else:
                 logger.debug(
@@ -237,6 +253,17 @@ def move_resource(self, resource: Resource) -> FileChange:
             source=self.subproject.parent_project.resolve_file_path(resource),
         )
 
+    def copy_jinja_block(self, resource: Resource, jinja_block: JinjaBlock) -> FileChange:
+        """Move an existing jinja block to a new project"""
+
+        return FileChange(
+            operation=Operation.Append,
+            entity_type=EntityType.Code,
+            identifier=resource.name,
+            path=self.subproject.resolve_file_path(resource),
+            data=jinja_block.content,
+        )
+
     def copy_resource(self, resource: Resource) -> FileChange:
         """
         Copy a resource file from one project to another

dbt_meshify/storage/file_content_editors.py

@@ -107,6 +107,18 @@ def add(change: FileChange):
 
         RawFileManager.write_file(path=change.path, content=change.data)
 
+    @staticmethod
+    def append(change: FileChange):
+        """Append data to an existing file."""
+
+        if not change.path.parent.exists():
+            change.path.parent.mkdir(parents=True, exist_ok=True)
+
+        if change.data is None:
+            return RawFileManager.touch_file(change.path)
+
+        RawFileManager.append_file(path=change.path, content=change.data)
+
     @staticmethod
     def update(change: FileChange):
         """Update data to a new file."""

dbt_meshify/storage/file_manager.py

@@ -62,6 +62,12 @@ def write_file(path: Path, content: str) -> None:
         """Write a string value to a file in the filesystem"""
         path.write_text(content)
 
+    @staticmethod
+    def append_file(path: Path, content: str) -> None:
+        """Append a string value to a file in the filesystem"""
+        with open(path, "a") as file:
+            file.write(content)
+
     @staticmethod
     def copy_file(source_path: Path, target_path: Path) -> None:
         if not target_path.parent.exists():

dbt_meshify/storage/jinja_blocks.py

@@ -0,0 +1,75 @@
+import re
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Set, Tuple
+
+
+@dataclass
+class JinjaBlock:
+    """
+    A data structure for tracking Jinja blocks of text. Includes the start and end character positions, and the content of the block
+    """
+
+    path: Path
+    block_type: str
+    name: str
+    start: int
+    end: int
+    content: str
+
+    @staticmethod
+    def find_block_range(file_content: str, block_type: str, name: str) -> Tuple[int, int]:
+        """Find the line number that a block started."""
+        start_line = None
+        end_line = None
+
+        for match in re.finditer(
+            r"{%-?\s+" + block_type + r"\s+" + name + r"([(a-zA-Z0-9=,_ )]*)\s-?%}",
+            file_content,
+            re.MULTILINE,
+        ):
+            start = match.span()[0]  # .span() gives tuple (start, end)
+            start_line = start  # file_content[:start].count("\n")
+            break
+
+        if start_line is None:
+            raise Exception(f"Unable to find a {block_type} block with the name {name}.")
+
+        for match in re.finditer(
+            r"{%-?\s+end" + block_type + r"\s+-?%}", file_content, re.MULTILINE
+        ):
+            end = match.span()[1]  # .span() gives tuple (start, end)
+            new_end_line = end  # file_content[:start].count("\n")
+
+            if new_end_line >= start_line:
+                end_line = new_end_line
+                break
+
+        if end_line is None:
+            raise Exception(f"Unable to find a the closing end{block_type} block for {name}.")
+
+        return start_line, end_line
+
+    @staticmethod
+    def isolate_content(file_content: str, start: int, end: int) -> str:
+        """Given content, a start position, and an end position, return the content of a Jinja block."""
+        return file_content[start:end]
+
+    @classmethod
+    def from_file(cls, path: Path, block_type: str, name: str) -> "JinjaBlock":
+        """Find a specific Jinja block within a file, based on the block type and the name."""
+
+        file_content = path.read_text()
+        start, end = cls.find_block_range(file_content, block_type, name)
+        content = cls.isolate_content(file_content=file_content, start=start, end=end)
+
+        return cls(
+            path=path, block_type=block_type, name=name, start=start, end=end, content=content
+        )
+
+
+def find_doc_reference(content: str) -> Set[str]:
+    """Find all doc block references within a string."""
+    matches = re.findall(r"{{\sdoc\(\'?\"?([a-zA-Z0-9_\-\.]+)\'?\"?\)\s}}", content)
+
+    return set(matches)

test-projects/split/split_proj/macros/_macros.yml

@@ -1,3 +1,5 @@
 macros:
   - name: cents_to_dollars
-    description: Converts cents to dollars
+    description: Converts cents to dollars
+  - name: dollars_to_cents
+    description: Converts dollars to cents

test-projects/split/split_proj/macros/cents_to_dollars.sql

@@ -3,3 +3,8 @@
 {% macro cents_to_dollars(column_name, precision=2) -%}
     ({{ column_name }} / 100)::{{ type_numeric() }}(16, {{ precision }})
 {%- endmacro %}
+
+
+{% macro dollars_to_cents(column_name) -%}
+    ({{ column_name }} * 100)::{{ type_numeric() }}(16, 0)
+{%- endmacro %}

test-projects/split/split_proj/models/docs.md

@@ -0,0 +1,3 @@
+{% docs customer_id %}
+The unique key for each customer.
+{% enddocs %}

test-projects/split/split_proj/models/marts/__models.yml

@@ -2,11 +2,12 @@ version: 2
 
 models:
   - name: customers
-    description: Customer overview data mart, offering key details for each unique
+    description:
+      Customer overview data mart, offering key details for each unique
       customer. One row per customer.
     columns:
       - name: customer_id
-        description: The unique key of the orders mart.
+        description: "{{ doc('customer_id') }}"
         tests:
           - not_null
           - unique
@@ -19,20 +20,24 @@ models:
       - name: last_ordered_at
         description: The timestamp of a customer's most recent order.
       - name: lifetime_spend_pretax
-        description: The sum of all the pre-tax subtotals of every order a customer
+        description:
+          The sum of all the pre-tax subtotals of every order a customer
           has placed.
       - name: lifetime_spend
-        description: The sum of all the order totals (including tax) that a customer
+        description:
+          The sum of all the order totals (including tax) that a customer
           has ever placed.
       - name: customer_type
-        description: Options are 'new' or 'returning', indicating if a customer has
+        description:
+          Options are 'new' or 'returning', indicating if a customer has
           ordered more than once or has only placed their first order to date.
         tests:
           - accepted_values:
               values: [new, returning]
 
   - name: orders
-    description: Order overview data mart, offering key details for each order inlcluding
+    description:
+      Order overview data mart, offering key details for each order inlcluding
       if it's a customer's first order and a food vs. drink item breakdown. One row
       per order.
     tests:
@@ -53,7 +58,8 @@ models:
               to: ref('stg_customers')
               field: customer_id
       - name: location_id
-        description: The foreign key relating to the location the order was placed
+        description:
+          The foreign key relating to the location the order was placed
           at.
       - name: order_total
         description: The total amount of the order in USD including tax.
@@ -74,19 +80,19 @@ models:
       - name: order_cost
         description: The sum of supply expenses to fulfill the order.
       - name: location_name
-        description: The full location name of where this order was placed. Denormalized
+        description:
+          The full location name of where this order was placed. Denormalized
           from `stg_locations`.
       - name: is_food_order
         description: A boolean indicating if this order included any food items.
       - name: is_drink_order
         description: A boolean indicating if this order included any drink items.
 
-
   - name: leaf_node
     description: A leaf node model that is not referenced by any other model.
     columns:
       - name: order_id
         description: The unique key of the leaf node.
         tests:
           - not_null
-          - unique
+          - unique

test-projects/split/split_proj/models/staging/__models.yml

@@ -5,7 +5,7 @@ models:
     description: Customer data with basic cleaning and transformation applied, one row per customer.
     columns:
       - name: customer_id
-        description: The unique key for each customer.
+        description: "{{ doc('customer_id') }}"
         tests:
           - not_null
           - unique