[validation] More detailed error diagnostics for validatePreserveExistingMemo

--- 

This should make it easier to grep through error diagnostics to understand state 
of the codebase: 

- no matching dependences -> likely that source is ignoring eslint failures 

- differences in ref.current access -> non-backwards compatible refs 

- subpath -> should be fixable in the compiler (unless source is ignore eslint 
failures)

compiler/packages/babel-plugin-react-forget/src/Validation/ValidatePreservedManualMemoization.ts

@@ -102,10 +102,41 @@ function prettyPrintScopeDependency(val: ReactiveScopeDependency): string {
   return `${rootStr}${val.path.length > 0 ? "." : ""}${val.path.join(".")}`;
 }
 
+enum CompareDependencyResult {
+  Ok = 0,
+  RootDifference = 1,
+  PathDifference = 2,
+  Subpath = 3,
+  RefAccessDifference = 4,
+}
+
+function merge(
+  a: CompareDependencyResult,
+  b: CompareDependencyResult
+): CompareDependencyResult {
+  return Math.max(a, b);
+}
+
+function getCompareDependencyResultDescription(
+  result: CompareDependencyResult
+): string {
+  switch (result) {
+    case CompareDependencyResult.Ok:
+      return "dependencies equal";
+    case CompareDependencyResult.RootDifference:
+    case CompareDependencyResult.PathDifference:
+      return "inferred different dependency than source";
+    case CompareDependencyResult.RefAccessDifference:
+      return "differences in ref.current access";
+    case CompareDependencyResult.Subpath:
+      return "inferred less specific property than source";
+  }
+}
+
 function compareDeps(
   inferred: ManualMemoDependency,
   source: ManualMemoDependency
-): boolean {
+): CompareDependencyResult {
   const rootsEqual =
     (inferred.root.kind === "Global" &&
       source.root.kind === "Global" &&
@@ -114,7 +145,7 @@ function compareDeps(
       source.root.kind === "NamedLocal" &&
       inferred.root.value.identifier.id === source.root.value.identifier.id);
   if (!rootsEqual) {
-    return false;
+    return CompareDependencyResult.RootDifference;
   }
 
   let isSubpath = true;
@@ -131,9 +162,20 @@ function compareDeps(
       (inferred.path.length >= source.path.length &&
         !inferred.path.includes("current")))
   ) {
-    return true;
+    return CompareDependencyResult.Ok;
   } else {
-    return false;
+    if (isSubpath) {
+      if (
+        source.path.includes("current") ||
+        inferred.path.includes("current")
+      ) {
+        return CompareDependencyResult.RefAccessDifference;
+      } else {
+        return CompareDependencyResult.Subpath;
+      }
+    } else {
+      return CompareDependencyResult.PathDifference;
+    }
   }
 }
 
@@ -197,9 +239,13 @@ function validateInferredDep(
       return;
     }
   }
+  let errorDiagnostic: CompareDependencyResult | null = null;
   for (const originalDep of validDepsInMemoBlock) {
-    if (compareDeps(normalizedDep, originalDep)) {
+    const compareResult = compareDeps(normalizedDep, originalDep);
+    if (compareResult === CompareDependencyResult.Ok) {
       return;
+    } else {
+      errorDiagnostic = merge(errorDiagnostic ?? compareResult, compareResult);
     }
   }
   errorState.push({
@@ -210,7 +256,11 @@ function validateInferredDep(
       dep
     )}\`, but the source dependencies were [${validDepsInMemoBlock
       .map((dep) => printManualMemoDependency(dep, true))
-      .join(", ")}]`,
+      .join(", ")}]. Detail: ${
+      errorDiagnostic
+        ? getCompareDependencyResultDescription(errorDiagnostic)
+        : "none"
+    }`,
     loc: GeneratedSource,
     suggestions: null,
   });

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.maybe-invalid-useCallback-read-maybeRef.expect.md

@@ -17,7 +17,7 @@ function useHook(maybeRef) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `maybeRef.current`, but the source dependencies were [maybeRef]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `maybeRef.current`, but the source dependencies were [maybeRef]. Detail: differences in ref.current access
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.maybe-invalid-useMemo-read-maybeRef.expect.md

@@ -17,7 +17,7 @@ function useHook(maybeRef, shouldRead) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `maybeRef.current`, but the source dependencies were [shouldRead, maybeRef]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `maybeRef.current`, but the source dependencies were [shouldRead, maybeRef]. Detail: differences in ref.current access
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-aliased-var.expect.md

@@ -19,7 +19,7 @@ function useHook(x) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `aliasedX`, but the source dependencies were [x, aliasedProp]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `aliasedX`, but the source dependencies were [x, aliasedProp]. Detail: inferred different dependency than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-conditional-access-noAlloc.expect.md

@@ -25,7 +25,7 @@ export const FIXTURE_ENTRYPOINT = {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propB`, but the source dependencies were [propA, propB.x.y]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propB`, but the source dependencies were [propA, propB.x.y]. Detail: inferred less specific property than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-infer-less-specific-conditional-access.expect.md

@@ -24,7 +24,7 @@ function Component({ propA, propB }) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]. Detail: inferred less specific property than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useCallback-property-call-dep.expect.md

@@ -17,7 +17,7 @@ function Component({ propA }) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.x]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.x]. Detail: inferred less specific property than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-aliased-var.expect.md

@@ -19,7 +19,7 @@ function useHook(x) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `x`, but the source dependencies were [aliasedX, aliasedProp]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `x`, but the source dependencies were [aliasedX, aliasedProp]. Detail: inferred different dependency than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-infer-less-specific-conditional-access.expect.md

@@ -24,9 +24,9 @@ function Component({ propA, propB }) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]. Detail: inferred less specific property than source
 
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propB`, but the source dependencies were [propA.a, propB.x.y]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propB`, but the source dependencies were [propA.a, propB.x.y]. Detail: inferred less specific property than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-infer-less-specific-conditional-value-block.expect.md

@@ -24,9 +24,9 @@ function Component({ propA, propB }) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.a, propB.x.y]. Detail: inferred less specific property than source
 
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propB`, but the source dependencies were [propA.a, propB.x.y]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propB`, but the source dependencies were [propA.a, propB.x.y]. Detail: inferred less specific property than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-property-call-chained-object.expect.md

@@ -19,7 +19,7 @@ function Component({ propA }) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.x]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.x]. Detail: inferred less specific property than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-property-call-dep.expect.md

@@ -17,7 +17,7 @@ function Component({ propA }) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.x]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `propA`, but the source dependencies were [propA.x]. Detail: inferred less specific property than source
 ```
           
       

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/preserve-memo-validation/error.useMemo-unrelated-mutation-in-depslist.expect.md

@@ -30,7 +30,7 @@ function useFoo(input1) {
 ## Error
 
 ```
-[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `input1`, but the source dependencies were [y]
+[ReactForget] Todo: Could not preserve manual memoization because an inferred dependency does not match the dependency list in source. The inferred dependency was `input1`, but the source dependencies were [y]. Detail: inferred different dependency than source
 ```