mirror: remove legacy non-EAV `extract` (#1346)

Test Plan:
Existing tests suffice, retaining full coverage.

wchargin-branch: mirror-eav-prune-extract

src/graphql/mirror.js

@@ -145,8 +145,8 @@ export class Mirror {
    *
    *     NOTE: A previous version of the schema used a separate
    *     primitives table for each GraphQL object type. These
-   *     `primitives_*` tables are still written, but are no longer read
+   *     `primitives_*` tables are still written, but are no longer
-   *     by default. They will be removed entirely in a future change.
+   *     read. They will be removed entirely in a future change.
    *
    * We refer to node and primitive data together as "own data", because
    * this is the data that can be queried uniformly for all elements of
@@ -1640,14 +1640,7 @@ export class Mirror {
    * may be removed or changed at any time. For information about its
    * semantics, read the current source code.
    */
-  extract(
+  extract(rootId: Schema.ObjectId): mixed {
-    rootId: Schema.ObjectId,
-    options?: {|+useEavPrimitives?: boolean|}
-  ): mixed {
-    const fullOptions = {
-      ...{useEavPrimitives: true},
-      ...(options || {}),
-    };
     const db = this._db;
     return _inTransaction(db, () => {
       // We'll compute the transitive dependencies and store them into a
@@ -1688,10 +1681,6 @@ export class Mirror {
             ON objects.id = transitive_dependencies.id
           `
         ).run({rootId});
-        const typenames: $ReadOnlyArray<Schema.Typename> = db
-          .prepare(`SELECT DISTINCT typename FROM ${temporaryTableName}`)
-          .pluck()
-          .all();
 
         // Check to make sure all required objects and connections have
         // been updated at least once.
@@ -1736,12 +1725,12 @@ export class Mirror {
         // Constructing the result set inherently requires mutation,
         // because the object graph can have cycles. We start by
         // creating a record for each object, with just that object's
-        // typename and ID (and, in legacy non-EAV mode, all primitive
+        // typename and ID. Then, we link in primitives, node
-        // data). Then, we link in primitives (except in legacy non-EAV
+        // references, and connection entries.
-        // mode), node references, and connection entries.
         const allObjects: Map<Schema.ObjectId, Object> = new Map();
-        if (fullOptions.useEavPrimitives) {
+
-          // Initialize `allObjects`.
+        // Initialize `allObjects`.
+        {
           const getObjects = db.prepare(
             `SELECT id AS id, typename AS typename FROM ${temporaryTableName}`
           );
@@ -1751,8 +1740,10 @@ export class Mirror {
               __typename: object.typename,
             });
           }
+        }
 
-          // Fill in primitive data.
+        // Fill in primitive data.
+        {
           const getPrimitives = db.prepare(
             dedent`\
               SELECT
@@ -1801,99 +1792,6 @@ export class Mirror {
               }
             }
           }
-        } else {
-          // Legacy non-EAV mode.
-          for (const typename of typenames) {
-            const objectType = this._schemaInfo.objectTypes[typename];
-            // istanbul ignore if: should not be possible using the
-            // publicly accessible APIs
-            if (objectType == null) {
-              throw new Error(
-                `Corruption: unknown object type ${JSON.stringify(typename)}`
-              );
-            }
-            const primitivesTableName = _primitivesTableName(typename);
-            const selections: $ReadOnlyArray<string> = [].concat(
-              [`${primitivesTableName}.id AS id`],
-              objectType.primitiveFieldNames.map(
-                (fieldname) =>
-                  `${primitivesTableName}."${fieldname}" AS "${fieldname}"`
-              ),
-              objectType.nestedFieldNames.map(
-                (fieldname) =>
-                  `${primitivesTableName}."${fieldname}" AS "${fieldname}"`
-              ),
-              ...objectType.nestedFieldNames.map((f1) =>
-                Object.keys(objectType.nestedFields[f1].primitives).map(
-                  (f2) =>
-                    `${primitivesTableName}."${f1}.${f2}" AS "${f1}.${f2}"`
-                )
-              )
-            );
-            const rows: $ReadOnlyArray<{|
-              +id: Schema.ObjectId,
-              +[Schema.Fieldname]: string | 0 | 1,
-            |}> = db
-              .prepare(
-                dedent`\
-                  SELECT ${selections.join(", ")}
-                  FROM ${temporaryTableName} JOIN ${primitivesTableName}
-                  USING (id)
-                `
-              )
-              .all();
-            for (const row of rows) {
-              const object = {};
-              object.id = row.id;
-              object.__typename = typename;
-              for (const fieldname of objectType.nestedFieldNames) {
-                const isPresent: string | 0 | 1 = row[fieldname];
-                // istanbul ignore if: should not be reachable
-                if (isPresent !== 0 && isPresent !== 1) {
-                  const s = JSON.stringify;
-                  const id = object.id;
-                  throw new Error(
-                    `Corruption: nested field ${s(fieldname)} on ${s(id)} ` +
-                      `set to ${String(isPresent)}`
-                  );
-                }
-                if (isPresent) {
-                  // We'll add primitives and links onto this object.
-                  object[fieldname] = {};
-                } else {
-                  object[fieldname] = null;
-                }
-              }
-              for (const key of Object.keys(row)) {
-                if (key === "id") continue;
-                const rawValue = row[key];
-                if (rawValue === 0 || rawValue === 1) {
-                  // Name of a nested field; already processed.
-                  continue;
-                }
-                const value = JSON.parse(rawValue);
-                const parts = key.split(".");
-                switch (parts.length) {
-                  case 1:
-                    object[key] = value;
-                    break;
-                  case 2: {
-                    const [nestName, eggName] = parts;
-                    if (object[nestName] !== null) {
-                      object[nestName][eggName] = value;
-                    }
-                    break;
-                  }
-                  // istanbul ignore next: should not be possible
-                  default:
-                    throw new Error(
-                      `Corruption: bad field name: ${JSON.stringify(key)}`
-                    );
-                }
-              }
-              allObjects.set(object.id, object);
-            }
-          }
         }
 
         // Add links.

src/graphql/mirror.test.js

@@ -3416,10 +3416,10 @@ describe("graphql/mirror", () => {
     }
 
     describe("extract", () => {
-      // We'll run under both legacy and EAV modes. In each case, hide
+      // Test in EAV mode, hiding the tables corresponding to the legacy
-      // the tables corresponding to the other mode to catch any
+      // mode to catch any accidental reads. (We hide and unhide rather
-      // accidental reads. (We hide and unhide rather than deleting
+      // than deleting because some test cases call `extract` multiple
-      // because some test cases call `extract` multiple times.)
+      // times.)
       function hiddenName(name) {
         return `${name}_DO_NOT_READ`;
       }
@@ -3430,57 +3430,27 @@ describe("graphql/mirror", () => {
         db.prepare(`ALTER TABLE ${hiddenName(name)} RENAME TO ${name}`).run();
       }
 
-      describe("with legacy type-specific primitives", () => {
+      testExtract((mirror, id) => {
-        testExtract((mirror, id) => {
+        const legacyTables = mirror._db
-          hideTable(mirror._db, "primitives");
+          .prepare(
-          try {
+            "SELECT name FROM sqlite_master " +
-            return mirror.extract(id, {useEavPrimitives: false});
+              "WHERE type = 'table' AND name LIKE 'primitives_%'"
-          } finally {
+          )
-            unhideTable(mirror._db, "primitives");
+          .pluck()
-          }
+          .all();
-        });
+        if (legacyTables.length === 0) {
-      });
+          throw new Error("Found no type-specific primitives tables?");
-
+        }
-      describe("with EAV primitives", () => {
+        for (const table of legacyTables) {
-        testExtract((mirror, id) => {
+          hideTable(mirror._db, table);
-          const legacyTables = mirror._db
+        }
-            .prepare(
+        try {
-              "SELECT name FROM sqlite_master " +
+          return mirror.extract(id);
-                "WHERE type = 'table' AND name LIKE 'primitives_%'"
+        } finally {
-            )
-            .pluck()
-            .all();
-          if (legacyTables.length === 0) {
-            throw new Error("Found no type-specific primitives tables?");
-          }
           for (const table of legacyTables) {
-            hideTable(mirror._db, table);
+            unhideTable(mirror._db, table);
           }
-          try {
+        }
-            return mirror.extract(id, {useEavPrimitives: true});
-          } finally {
-            for (const table of legacyTables) {
-              unhideTable(mirror._db, table);
-            }
-          }
-        });
-      });
-
-      it("works with default options", () => {
-        // Simple sanity check.
-        const db = new Database(":memory:");
-        const schema = buildGithubSchema();
-        const mirror = new Mirror(db, schema);
-        mirror.registerObject({typename: "SubscribedEvent", id: "sub"});
-        const update = mirror._createUpdate(new Date(123));
-        mirror._updateOwnData(update, [
-          {__typename: "SubscribedEvent", id: "sub", actor: null},
-        ]);
-        expect(mirror.extract("sub")).toEqual({
-          __typename: "SubscribedEvent",
-          id: "sub",
-          actor: null,
-        });
       });
     });