feat: deterministic tested_by edges + dashboard badge (#113)

.gitignore

@@ -11,3 +11,5 @@ coverage/
 .worktrees/
 homepage/public/demo/
 .private/
+__pycache__/
+*.pyc

understand-anything-plugin/agents/file-analyzer.md

@@ -213,7 +213,9 @@ Using the script's structural data and file categories, create edges:
 | `implements` | A class implements an interface in the project | `0.9` | `forward` |
 | `exports` | File exports a function or class node you created (only for exported items — use IN ADDITION to `contains`, not instead of it) | `0.8` | `forward` |
 | `depends_on` | File has runtime dependency on another project file (broader than imports -- includes dynamic requires, lazy loads) | `0.6` | `forward` |
-| `tested_by` | Source file is tested by a test file (infer from test file imports and naming conventions) | `0.5` | `forward` |
+| `tested_by` | Production file is exercised by a test file. Emit when you see the test importing/using the production file. Use direction `production → test` if you can; the merge script will flip inverted edges and dedupe. | `0.5` | `forward` |
+
+**Note on `tested_by`:** It's fine to emit even if you're unsure of the direction (you typically see the relationship while analyzing the *test* file, where the import points back at production). The merge script (`merge-batch-graphs.py`) canonicalizes direction to `production → test` and drops semantically broken edges (test↔test, prod↔prod, orphan endpoint). Path-convention pairing supplements anything you miss.
 
 #### Edges for non-code files:
 

understand-anything-plugin/packages/dashboard/src/components/CustomNode.tsx

@@ -151,9 +151,19 @@ function CustomNodeComponent({
           <span className={`text-[10px] font-semibold uppercase tracking-wider ${textColor}`}>
             {data.nodeType}
           </span>
-          <span className={`text-[9px] font-mono ${complexityColor}`}>
-            {data.complexity}
-          </span>
+          <div className="flex items-center gap-1.5">
+            <span className={`text-[9px] font-mono ${complexityColor}`}>
+              {data.complexity}
+            </span>
+            {data.tags?.includes("tested") && (
+              <span
+                className="inline-block w-1.5 h-1.5 rounded-full bg-node-function shadow-[0_0_4px_rgba(90,158,111,0.6)]"
+                role="img"
+                aria-label="Tested"
+                title="Has tests"
+              />
+            )}
+          </div>
         </div>
 
         <div className="text-sm font-serif text-text-primary truncate" title={data.label}>

understand-anything-plugin/packages/dashboard/src/components/GraphView.tsx

@@ -533,6 +533,7 @@ function useLayerDetailTopology(): LayerDetailTopology & {
           nodeType: node.type,
           summary: node.summary,
           complexity: node.complexity,
+          tags: node.tags,
           isHighlighted: false,
           searchScore: undefined,
           isSelected: false,
@@ -908,6 +909,7 @@ function buildCustomFlowNode(
       nodeType: node.type,
       summary: node.summary,
       complexity: node.complexity,
+      tags: node.tags,
       isHighlighted: false,
       searchScore: undefined,
       isSelected: false,

understand-anything-plugin/skills/understand/SKILL.md

@@ -278,6 +278,8 @@ This script reads all `batch-*.json` files from `$PROJECT_ROOT/.understand-anyth
 - Drops dangling edges referencing missing nodes
 - Logs all corrections and dropped items to stderr
 
+The merge script also runs a `tested_by` linker that canonicalizes test-coverage edges in two passes. **Pass 1** walks LLM-emitted `tested_by` edges and flips inverted ones in place (the LLM systematically emits `test → production` because it sees the import only when analyzing the test file); semantically broken edges (test↔test, prod↔prod, orphan endpoints) are dropped. **Pass 2** supplements with path-convention pairings (`X.ts` ↔ `X.test.ts`, JS/TS `__tests__/` and `<dir>/test/` walk-out, Python in-package `tests/`, Go `_test.go` sibling, Maven/Gradle `src/test/...` ↔ `src/main/...`, .NET `<svc>/tests/` ↔ `<svc>/src/...` and `<App>.Tests/` ↔ `<App>/`). Production nodes that end up sourcing any `tested_by` edge get a `"tested"` tag. All resulting edges run `production → test`.
+
 Output: `$PROJECT_ROOT/.understand-anything/intermediate/assembled-graph.json`
 
 Include the script's warnings in `$PHASE_WARNINGS` for the reviewer.