add match!

docs/workflow_drafts.md

@@ -209,6 +209,33 @@ Creates one boolean decision step. The condition uses the same JSON shape as
 The draft adapter lowers this through `WorkflowBuilder.when()`. The draft step
 id becomes the generated condition entry id, so other routes can target it.
 
+### `match`
+
+Matches one graph value against ordered equality cases.
+
+```json
+{
+  "match": {
+    "value": "state.status",
+    "cases": [
+      {
+        "equals": "ready",
+        "then": "run"
+      },
+      {
+        "equals": "waiting",
+        "then": "pause"
+      }
+    ],
+    "default": "__end__"
+  }
+}
+```
+
+Cases are a list rather than a JSON object so values such as `1`, `"1"`, and
+`true` are not silently coerced into object keys. The draft adapter lowers this
+through `WorkflowBuilder.match()`.
+
 ### `choose`
 
 Creates an ordered first-true decision chain.
@@ -243,8 +270,8 @@ Creates an ordered first-true decision chain.
 ```
 
 `choose` lowers through `WorkflowBuilder.choose()` and expands to generated
-condition nodes. It replaces the deprecated `route()` concept for draft JSON;
+condition nodes. `match`, `when`, and `choose` replace the deprecated `route()`
-there is intentionally no draft `route` step kind.
+concept for draft JSON; there is intentionally no draft `route` step kind.
 
 ## Draft Tools
 

src/wf_artifacts/drafts/__init__.py

@@ -11,6 +11,8 @@ from .models import (
     DraftForeachStep,
     DraftInterruptStep,
     DraftJoinStep,
+    DraftMatchCase,
+    DraftMatchStep,
     DraftWhenStep,
     DraftUseStep,
     WorkflowDraft,
@@ -23,6 +25,8 @@ __all__ = [
     "DraftForeachStep",
     "DraftInterruptStep",
     "DraftJoinStep",
+    "DraftMatchCase",
+    "DraftMatchStep",
     "DraftWhenStep",
     "DraftUseStep",
     "WorkflowDraft",

src/wf_artifacts/drafts/adapter.py

@@ -1,16 +1,18 @@
 from __future__ import annotations
 
 from wf_authoring import WorkflowBuilder
+from wf_authoring.dsl import PathExpr
 from wf_core import JoinNode, Workflow
 
 from .models import (
+    DraftChooseStep,
     DraftForeachStep,
     DraftInterruptStep,
     DraftJoinStep,
+    DraftMatchStep,
     DraftStep,
     DraftUseStep,
     DraftWhenStep,
-    DraftChooseStep,
     WorkflowDraft,
 )
 
@@ -79,4 +81,11 @@ def _add_step(builder: WorkflowBuilder, step_id: str, step: DraftStep):
             id=step_id,
             default=step.choose.default,
         ).entry
+    if isinstance(step, DraftMatchStep):
+        return builder.match(
+            PathExpr(step.match.value),
+            {case.equals: case.then for case in step.match.cases},
+            id=step_id,
+            default=step.match.default,
+        ).entry
     raise TypeError(f"unsupported draft step {type(step)!r}")

src/wf_artifacts/drafts/models.py

@@ -7,7 +7,9 @@ from pydantic import BaseModel, Field, model_validator
 from wf_core.models.conditions import Condition
 
 JsonObject = dict[str, Any]
-STEP_KIND_KEYS = frozenset({"use", "foreach", "interrupt", "join", "when", "choose"})
+STEP_KIND_KEYS = frozenset(
+    {"use", "foreach", "interrupt", "join", "when", "choose", "match"}
+)
 
 
 class DraftUseStep(BaseModel):
@@ -91,6 +93,27 @@ class DraftChooseStep(BaseModel):
     choose: DraftChoosePayload
 
 
+class DraftMatchCase(BaseModel):
+    """One ordered equality case in a draft match decision."""
+
+    equals: Any
+    then: str
+
+
+class DraftMatchPayload(BaseModel):
+    """Payload for matching one graph value against ordered equality cases."""
+
+    value: str
+    cases: list[DraftMatchCase] = Field(min_length=1)
+    default: str = "__end__"
+
+
+class DraftMatchStep(BaseModel):
+    """Draft step that delegates equality decisions to `WorkflowBuilder.match`."""
+
+    match: DraftMatchPayload
+
+
 DraftStep = (
     DraftUseStep
     | DraftForeachStep
@@ -98,6 +121,7 @@ DraftStep = (
     | DraftJoinStep
     | DraftWhenStep
     | DraftChooseStep
+    | DraftMatchStep
 )
 
 

tests/artifacts/test_draft_adapter.py

@@ -121,3 +121,47 @@ def test_adapter_lowers_choose_step_through_builder() -> None:
         ("pick_2", "true", "fallback"),
         ("pick_2", "false", "__end__"),
     ]
+
+
+def test_adapter_lowers_match_step_through_builder() -> None:
+    draft = WorkflowDraft.model_validate(
+        {
+            "name": "match_example",
+            "input_schema": {},
+            "state_schema": {"fields": {}},
+            "output_schema": {},
+            "start": "match_status",
+            "steps": {
+                "match_status": {
+                    "match": {
+                        "value": "state.status",
+                        "cases": [
+                            {"equals": "ready", "then": "ready"},
+                            {"equals": "waiting", "then": "waiting"},
+                        ],
+                        "default": "__end__",
+                    }
+                },
+                "ready": {"use": "demo.ready"},
+                "waiting": {"use": "demo.waiting"},
+            },
+            "routes": {
+                "ready": {"ok": "__end__"},
+                "waiting": {"ok": "__end__"},
+            },
+        }
+    )
+
+    workflow = build_workflow_from_draft(draft)
+    condition_ids = [
+        node.id for node in workflow.nodes if isinstance(node, ConditionNode)
+    ]
+
+    assert condition_ids == ["match_status", "match_status_2"]
+    assert workflow.start == "match_status"
+    assert [(edge.from_, edge.outcome, edge.to) for edge in workflow.edges[:4]] == [
+        ("match_status", "true", "ready"),
+        ("match_status", "false", "match_status_2"),
+        ("match_status_2", "true", "waiting"),
+        ("match_status_2", "false", "__end__"),
+    ]

tests/artifacts/test_draft_models.py

@@ -7,6 +7,7 @@ from pydantic import ValidationError
 
 from wf_artifacts.drafts import (
     DraftChooseStep,
+    DraftMatchStep,
     DraftUseStep,
     DraftWhenStep,
     WorkflowDraft,
@@ -87,6 +88,30 @@ def test_workflow_draft_accepts_choose_step() -> None:
     assert isinstance(draft.steps["choose_next"], DraftChooseStep)
 
 
+def test_workflow_draft_accepts_match_step() -> None:
+    draft = WorkflowDraft.model_validate(
+        {
+            **_keyed_echo_draft(),
+            "start": "match_status",
+            "steps": {
+                **_keyed_echo_draft()["steps"],
+                "match_status": {
+                    "match": {
+                        "value": "state.status",
+                        "cases": [
+                            {"equals": "ready", "then": "echo"},
+                            {"equals": "done", "then": "__end__"},
+                        ],
+                        "default": "__end__",
+                    }
+                },
+            },
+        }
+    )
+
+    assert isinstance(draft.steps["match_status"], DraftMatchStep)
+
+
 def _keyed_echo_draft() -> dict[str, Any]:
     return {
         "name": "echo",