Migrating remaining JS modules to Typescript (part 1)

packages/turf-angle/test.js

@@ -3,7 +3,7 @@ const path = require("path");
 const { glob } = require("glob");
 const { loadJsonFileSync } = require("load-json-file");
 const { writeJsonFileSync } = require("write-json-file");
-const sector = require("@turf/sector");
+const sector = require("@turf/sector").default;
 const bearing = require("@turf/bearing").default;
 const truncate = require("@turf/truncate").default;
 const distance = require("@turf/distance").default;

packages/turf-difference/index.js → packages/turf-difference/index.ts

@@ -1,4 +1,5 @@
-import polygonClipping from "polygon-clipping";
+import { Polygon, MultiPolygon, Feature, FeatureCollection } from "geojson";
+import polygonClipping, { Geom } from "polygon-clipping";
 import { polygon, multiPolygon } from "@turf/helpers";
 import { geomEach } from "@turf/meta";
 
@@ -35,20 +36,22 @@ import { geomEach } from "@turf/meta";
  * //addToMap
  * var addToMap = [polygon1, polygon2, difference];
  */
-function difference(features) {
-  const geoms = [];
+function difference(
+  features: FeatureCollection<Polygon | MultiPolygon>
+): Feature<Polygon | MultiPolygon> | null {
+  const geoms: Array<Geom> = [];
 
   geomEach(features, (geom) => {
-    geoms.push(geom.coordinates);
+    geoms.push(geom.coordinates as Geom);
   });
 
   if (geoms.length < 2) {
     throw new Error("Must have at least two features");
   }
 
-  var properties = features.features[0].properties || {};
+  const properties = features.features[0].properties || {};
 
-  var differenced = polygonClipping.difference(geoms[0], ...geoms.slice(1));
+  const differenced = polygonClipping.difference(geoms[0], ...geoms.slice(1));
   if (differenced.length === 0) return null;
   if (differenced.length === 1) return polygon(differenced[0], properties);
   return multiPolygon(differenced, properties);

packages/turf-difference/package.json

@@ -25,37 +25,40 @@
   "exports": {
     "./package.json": "./package.json",
     ".": {
-      "types": "./index.d.ts",
+      "types": "./dist/js/index.d.ts",
       "import": "./dist/es/index.js",
       "require": "./dist/js/index.js"
     }
   },
-  "types": "index.d.ts",
+  "types": "dist/js/index.d.ts",
   "sideEffects": false,
   "files": [
-    "dist",
-    "index.d.ts"
+    "dist"
   ],
   "scripts": {
     "bench": "tsx bench.js",
-    "build": "rollup -c ../../rollup.config.js && echo '{\"type\":\"module\"}' > dist/es/package.json",
+    "build": "npm-run-all --npm-path npm build:*",
+    "build:es": "tsc --outDir dist/es --module esnext --declaration false && echo '{\"type\":\"module\"}' > dist/es/package.json",
+    "build:js": "tsc",
     "docs": "tsx ../../scripts/generate-readmes.ts",
     "test": "npm-run-all --npm-path npm test:*",
     "test:tape": "tsx test.js"
   },
   "devDependencies": {
+    "@types/tape": "^4.2.32",
     "benchmark": "^2.1.4",
     "glob": "^10.3.10",
     "load-json-file": "^7.0.1",
     "npm-run-all": "^4.1.5",
-    "rollup": "^2.79.1",
     "tape": "^5.7.2",
     "tsx": "^3.14.0",
+    "typescript": "^5.2.2",
     "write-json-file": "^5.0.0"
   },
   "dependencies": {
     "@turf/helpers": "^7.0.0-alpha.2",
     "@turf/meta": "^7.0.0-alpha.2",
-    "polygon-clipping": "^0.15.3"
+    "polygon-clipping": "^0.15.3",
+    "tslib": "^2.6.2"
   }
 }

packages/turf-difference/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": "../../tsconfig.shared.json",
+  "compilerOptions": {
+    "outDir": "dist/js"
+  },
+  "files": ["index.ts"]
+}

packages/turf-directional-mean/index.ts

@@ -59,7 +59,7 @@ export default function directionalMean(
   } = {}
 ): DirectionalMeanLine {
   const isPlanar = !!options.planar; // you can't use options.planar || true here.
-  const isSegment: boolean = options.segment || false;
+  const isSegment: boolean = options.segment ?? false;
   let sigmaSin = 0;
   let sigmaCos = 0;
   let countOfLines = 0;

packages/turf-dissolve/index.js → packages/turf-dissolve/index.ts

@@ -1,8 +1,9 @@
-import { featureCollection, multiPolygon, isObject } from "@turf/helpers";
+import { Feature, FeatureCollection, Polygon } from "geojson";
+import { featureCollection, isObject, multiPolygon } from "@turf/helpers";
 import { collectionOf } from "@turf/invariant";
 import { featureEach } from "@turf/meta";
 import flatten from "@turf/flatten";
-import polygonClipping from "polygon-clipping";
+import polygonClipping, { Geom } from "polygon-clipping";
 
 /**
  * Dissolves a FeatureCollection of {@link polygon} features, filtered by an optional property name:value.
@@ -25,53 +26,68 @@ import polygonClipping from "polygon-clipping";
  * //addToMap
  * var addToMap = [features, dissolved]
  */
-function dissolve(fc, options) {
+function dissolve(
+  fc: FeatureCollection<Polygon>,
+  options: {
+    propertyName?: string;
+  } = {}
+): FeatureCollection<Polygon> {
   // Optional parameters
   options = options || {};
   if (!isObject(options)) throw new Error("options is invalid");
-  var propertyName = options.propertyName;
+  const { propertyName } = options;
 
   // Input validation
   collectionOf(fc, "Polygon", "dissolve");
 
   // Main
-  var outFeatures = [];
-  if (!options.propertyName) {
+  const outFeatures = [];
+  if (!propertyName) {
     return flatten(
       multiPolygon(
         polygonClipping.union.apply(
           null,
+          // List of polygons expressed as Position[][][] a.k.a. Geom[]
           fc.features.map(function (f) {
             return f.geometry.coordinates;
-          })
+          }) as [Geom, ...Geom[]]
         )
       )
     );
   } else {
-    var uniquePropertyVals = {};
+    // Group polygons by the value of their property named by propertyName
+    const uniquePropertyVals: { [key: string]: Feature[] } = {};
     featureEach(fc, function (feature) {
-      if (
-        !Object.prototype.hasOwnProperty.call(
-          uniquePropertyVals,
-          feature.properties[propertyName]
-        )
-      ) {
-        uniquePropertyVals[feature.properties[propertyName]] = [];
+      if (feature.properties) {
+        if (
+          !Object.prototype.hasOwnProperty.call(
+            uniquePropertyVals,
+            feature.properties[propertyName]
+          )
+        ) {
+          uniquePropertyVals[feature.properties[propertyName]] =
+            [] as Feature[];
+        }
+        uniquePropertyVals[feature.properties[propertyName]].push(feature);
       }
-      uniquePropertyVals[feature.properties[propertyName]].push(feature);
     });
-    var vals = Object.keys(uniquePropertyVals);
-    for (var i = 0; i < vals.length; i++) {
-      var mp = multiPolygon(
+    const vals = Object.keys(uniquePropertyVals);
+
+    // Export each group of polygons as a separate feature.
+    for (let i = 0; i < vals.length; i++) {
+      const mp = multiPolygon(
         polygonClipping.union.apply(
           null,
-          uniquePropertyVals[vals[i]].map(function (f) {
+          // List of polygons expressed as Position[][][] a.k.a. Geom[]
+          (uniquePropertyVals[vals[i]] as Feature<Polygon>[]).map(function (f) {
             return f.geometry.coordinates;
-          })
+          }) as [Geom, ...Geom[]]
         )
       );
-      mp.properties[propertyName] = vals[i];
-      outFeatures.push(mp);
+      if (mp && mp.properties) {
+        mp.properties[propertyName] = vals[i];
+        outFeatures.push(mp);
+      }
     }
   }
 

packages/turf-dissolve/package.json

@@ -28,38 +28,41 @@
   "exports": {
     "./package.json": "./package.json",
     ".": {
-      "types": "./index.d.ts",
+      "types": "./dist/js/index.d.ts",
       "import": "./dist/es/index.js",
       "require": "./dist/js/index.js"
     }
   },
-  "types": "index.d.ts",
+  "types": "dist/js/index.d.ts",
   "sideEffects": false,
   "files": [
-    "dist",
-    "index.d.ts"
+    "dist"
   ],
   "scripts": {
     "bench": "tsx bench.js",
-    "build": "rollup -c ../../rollup.config.js && echo '{\"type\":\"module\"}' > dist/es/package.json",
+    "build": "npm-run-all --npm-path npm build:*",
+    "build:es": "tsc --outDir dist/es --module esnext --declaration false && echo '{\"type\":\"module\"}' > dist/es/package.json",
+    "build:js": "tsc",
     "docs": "tsx ../../scripts/generate-readmes.ts",
     "test": "npm-run-all --npm-path npm test:*",
     "test:tape": "tsx test.js"
   },
   "devDependencies": {
+    "@types/tape": "^4.2.32",
     "benchmark": "^2.1.4",
     "load-json-file": "^7.0.1",
     "npm-run-all": "^4.1.5",
-    "rollup": "^2.79.1",
     "tape": "^5.7.2",
     "tsx": "^3.14.0",
+    "typescript": "^5.2.2",
     "write-json-file": "^5.0.0"
   },
   "dependencies": {
     "@turf/flatten": "^7.0.0-alpha.2",
     "@turf/helpers": "^7.0.0-alpha.2",
     "@turf/invariant": "^7.0.0-alpha.2",
     "@turf/meta": "^7.0.0-alpha.2",
-    "polygon-clipping": "^0.15.3"
+    "polygon-clipping": "^0.15.3",
+    "tslib": "^2.6.2"
   }
 }

packages/turf-dissolve/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": "../../tsconfig.shared.json",
+  "compilerOptions": {
+    "outDir": "dist/js"
+  },
+  "files": ["index.ts"]
+}

packages/turf-distance-weight/index.ts

@@ -59,9 +59,9 @@ export default function distanceWeight(
   options = options || {};
   const threshold = options.threshold || 10000;
   const p = options.p || 2;
-  const binary = options.binary || false;
+  const binary = options.binary ?? false;
   const alpha = options.alpha || -1;
-  const rowTransform = options.standardization || false;
+  const rowTransform = options.standardization ?? false;
 
   const features: Array<Feature<Point>> = [];
   featureEach(fc, (feature) => {