Make BaseTarget parameters getters stricter (#1534)

## Context


#1520 (comment)

## What

This adds a generic to `BaseTarget`, which is expected to receive the
type of the subclass' parameters. This tries its best to enforce that is
the case, and ensures implementations of `getCloneParameters` return
that declared type.

## Checklist

- [ ] I have added
[tests](https://www.cursorless.org/docs/contributing/test-case-recorder/)
- [ ] I have updated the
[docs](https://github.com/cursorless-dev/cursorless/tree/main/docs) and
[cheatsheet](https://github.com/cursorless-dev/cursorless/tree/main/cursorless-talon/src/cheatsheet)
- [ ] I have not broken the cheatsheet

Author: auscompgeek

packages/cursorless-engine/src/processTargets/targets/BaseTarget.ts

@@ -15,20 +15,32 @@ import {
   createContinuousRangeUntypedTarget,
 } from "../targetUtil/createContinuousRange";
 
-/** Parameters supported by most target classes */
-export interface CommonTargetParameters {
+/** Parameters supported by all target classes */
+export interface MinimumTargetParameters {
   readonly editor: TextEditor;
   readonly isReversed: boolean;
-  readonly contentRange: Range;
   readonly thatTarget?: Target;
 }
 
+/** Parameters supported by most target classes */
+export interface CommonTargetParameters extends MinimumTargetParameters {
+  readonly contentRange: Range;
+}
+
 export interface CloneWithParameters {
   readonly thatTarget?: Target;
   readonly contentRange?: Range;
 }
 
-export default abstract class BaseTarget implements Target {
+/**
+ * An abstract target. All targets subclass this.
+ *
+ * @template TParameters The constructor parameters.
+ */
+export default abstract class BaseTarget<
+  in out TParameters extends MinimumTargetParameters,
+> implements Target
+{
   protected readonly state: CommonTargetParameters;
   isLine = false;
   isToken = true;
@@ -39,7 +51,7 @@ export default abstract class BaseTarget implements Target {
   isNotebookCell = false;
   isWord = false;
 
-  constructor(parameters: CommonTargetParameters) {
+  constructor(parameters: TParameters & CommonTargetParameters) {
     this.state = {
       editor: parameters.editor,
       isReversed: parameters.isReversed,
@@ -112,16 +124,16 @@ export default abstract class BaseTarget implements Target {
     throw new NoContainingScopeError("boundary");
   }
 
-  readonly cloneWith = (parameters: CloneWithParameters) => {
+  private cloneWith(parameters: CloneWithParameters) {
     const constructor = Object.getPrototypeOf(this).constructor;
 
     return new constructor({
       ...this.getCloneParameters(),
       ...parameters,
     });
-  };
+  }
 
-  protected abstract getCloneParameters(): object;
+  protected abstract getCloneParameters(): TParameters;
 
   createContinuousRangeTarget(
     isReversed: boolean,
@@ -170,9 +182,8 @@ export default abstract class BaseTarget implements Target {
    *
    * @returns The object to be used for determining equality
    */
-  protected getEqualityParameters(): object {
-    const { thatTarget, ...otherCloneParameters } =
-      this.getCloneParameters() as { thatTarget?: Target };
+  protected getEqualityParameters(): Omit<TParameters, "thatTarget"> {
+    const { thatTarget, ...otherCloneParameters } = this.getCloneParameters();
 
     return {
       ...otherCloneParameters,

packages/cursorless-engine/src/processTargets/targets/DocumentTarget.ts

@@ -3,7 +3,7 @@ import { shrinkRangeToFitContent } from "../../util/selectionUtils";
 import BaseTarget, { CommonTargetParameters } from "./BaseTarget";
 import PlainTarget from "./PlainTarget";
 
-export default class DocumentTarget extends BaseTarget {
+export default class DocumentTarget extends BaseTarget<CommonTargetParameters> {
   insertionDelimiter = "\n";
   isLine = true;
 

packages/cursorless-engine/src/processTargets/targets/ImplicitTarget.ts

@@ -1,3 +1,4 @@
+import type { CommonTargetParameters } from "./BaseTarget";
 import BaseTarget from "./BaseTarget";
 
 /**
@@ -6,7 +7,7 @@ import BaseTarget from "./BaseTarget";
  * - The implicit destination in the command `"bring air"`
  * - The implicit anchor in the range `"take past air"`
  */
-export default class ImplicitTarget extends BaseTarget {
+export default class ImplicitTarget extends BaseTarget<CommonTargetParameters> {
   insertionDelimiter = "";
   isRaw = true;
   hasExplicitScopeType = false;

packages/cursorless-engine/src/processTargets/targets/InteriorTarget.ts

@@ -6,14 +6,14 @@ import {
   createContinuousRangeFromRanges,
   createContinuousRangeUntypedTarget,
 } from "../targetUtil/createContinuousRange";
-import BaseTarget, { CommonTargetParameters } from "./BaseTarget";
+import type { MinimumTargetParameters } from "./BaseTarget";
+import BaseTarget from "./BaseTarget";
 
-export interface InteriorTargetParameters
-  extends Omit<CommonTargetParameters, "contentRange"> {
+export interface InteriorTargetParameters extends MinimumTargetParameters {
   readonly fullInteriorRange: Range;
 }
 
-export default class InteriorTarget extends BaseTarget {
+export default class InteriorTarget extends BaseTarget<InteriorTargetParameters> {
   insertionDelimiter = " ";
   private readonly fullInteriorRange: Range;
 

packages/cursorless-engine/src/processTargets/targets/LineTarget.ts

@@ -3,9 +3,10 @@ import { Target } from "../../typings/target.types";
 import { expandToFullLine } from "../../util/rangeUtils";
 import { tryConstructPlainTarget } from "../../util/tryConstructTarget";
 import { createContinuousLineRange } from "../targetUtil/createContinuousRange";
+import type { CommonTargetParameters } from "./BaseTarget";
 import BaseTarget from "./BaseTarget";
 
-export default class LineTarget extends BaseTarget {
+export default class LineTarget extends BaseTarget<CommonTargetParameters> {
   insertionDelimiter = "\n";
   isLine = true;
 

packages/cursorless-engine/src/processTargets/targets/NotebookCellTarget.ts

@@ -3,7 +3,7 @@ import { TargetPosition } from "@cursorless/common";
 import BaseTarget, { CommonTargetParameters } from "./BaseTarget";
 import { removalUnsupportedForPosition } from "./PositionTarget";
 
-export default class NotebookCellTarget extends BaseTarget {
+export default class NotebookCellTarget extends BaseTarget<CommonTargetParameters> {
   insertionDelimiter = "\n";
   isNotebookCell = true;
 
@@ -32,7 +32,7 @@ interface NotebookCellPositionTargetParameters extends CommonTargetParameters {
   readonly position: TargetPosition;
 }
 
-export class NotebookCellPositionTarget extends BaseTarget {
+export class NotebookCellPositionTarget extends BaseTarget<NotebookCellPositionTargetParameters> {
   insertionDelimiter = "\n";
   isNotebookCell = true;
   public position: TargetPosition;

packages/cursorless-engine/src/processTargets/targets/ParagraphTarget.ts

@@ -10,10 +10,11 @@ import { expandToFullLine } from "../../util/rangeUtils";
 import { constructLineTarget } from "../../util/tryConstructTarget";
 import { isSameType } from "../../util/typeUtils";
 import { createContinuousLineRange } from "../targetUtil/createContinuousRange";
+import type { CommonTargetParameters } from "./BaseTarget";
 import BaseTarget from "./BaseTarget";
 import LineTarget from "./LineTarget";
 
-export default class ParagraphTarget extends BaseTarget {
+export default class ParagraphTarget extends BaseTarget<CommonTargetParameters> {
   insertionDelimiter = "\n\n";
   isLine = true;
 

packages/cursorless-engine/src/processTargets/targets/PlainTarget.ts

@@ -8,7 +8,7 @@ interface PlainTargetParameters extends CommonTargetParameters {
  * A target that has no leading or trailing delimiters so it's removal range
  * just consists of the content itself. Its insertion delimiter is empty string.
  */
-export default class PlainTarget extends BaseTarget {
+export default class PlainTarget extends BaseTarget<PlainTargetParameters> {
   insertionDelimiter = "";
 
   constructor(parameters: PlainTargetParameters) {

packages/cursorless-engine/src/processTargets/targets/PositionTarget.ts

@@ -10,7 +10,7 @@ interface PositionTargetParameters extends CommonTargetParameters {
   readonly isRaw: boolean;
 }
 
-export default class PositionTarget extends BaseTarget {
+export default class PositionTarget extends BaseTarget<PositionTargetParameters> {
   insertionDelimiter: string;
   isRaw: boolean;
   private position: TargetPosition;

packages/cursorless-engine/src/processTargets/targets/RawSelectionTarget.ts

@@ -1,11 +1,12 @@
+import type { CommonTargetParameters } from "./BaseTarget";
 import BaseTarget from "./BaseTarget";
 
 /**
  * A target that has no leading or trailing delimiters so it's removal range
  * just consists of the content itself. Its insertion delimiter will be
  * inherited from the source in the case of a bring after a bring before
  */
-export default class RawSelectionTarget extends BaseTarget {
+export default class RawSelectionTarget extends BaseTarget<CommonTargetParameters> {
   insertionDelimiter = "";
   isRaw = true;
   isToken = false;