refactor(frontend) :: convert the browser sources to TypeScript

frontend/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}

frontend/src/apexcharts.js → frontend/src/apexcharts.ts

@@ -1,16 +1,18 @@
+import type { ApexOptions } from "apexcharts";
 import ApexCharts from "apexcharts";
-import { align_series_for, xaxis_type_for } from "./chart_series.js";
-import { add_init_fn } from "./init.js";
-
-/**
- * @typedef {import("./chart_series.js").ChartSeries} ChartSeries
- * @typedef {import("./chart_series.js").Series} Series
- */
+import {
+  align_series_for,
+  type ChartSeries,
+  type Series,
+  xaxis_type_for,
+} from "./chart_series.ts";
+import { add_init_fn } from "./init.ts";
 
 const sqlpage_chart = (() => {
   function sqlpage_chart() {
-    /** @type {NodeListOf<HTMLElement>} */
-    const charts = document.querySelectorAll("[data-pre-init=chart]");
+    const charts = document.querySelectorAll<HTMLElement>(
+      "[data-pre-init=chart]",
+    );
     for (const c of charts) {
       try {
         build_sqlpage_chart(c);
@@ -50,24 +52,21 @@ const sqlpage_chart = (() => {
 
   const referenceColor = colorNames[isDarkTheme ? "gray-lt" : "gray"];
 
-  /** @typedef { {[property:string]: string|number|null} } ReferenceLine */
+  type ReferenceLine = { [property: string]: string | number | null };
 
-  /** @param {unknown} name @returns {string|undefined} */
-  const named_color = (name) =>
+  const named_color = (name: unknown): string | undefined =>
     typeof name === "string" ? colorNames[name] : undefined;
 
-  /** @param {string|number|null} name */
-  const reference_color = (name) => named_color(name) || referenceColor;
+  const reference_color = (name: string | number | null) =>
+    named_color(name) || referenceColor;
 
-  /**
-   * @param {ReferenceLine[]} rows - the rows that carry an xline or a yline
-   * @param {"x"|"y"} column - the column the reference is written in
-   * @param {"x"|"y"} axis - the apexcharts axis that column is drawn on
-   * @param {(value: any) => any} to_axis_value - puts a SQL value on the axis
-   * @returns {object[]} apexcharts axis annotations
-   */
-  function reference_lines(rows, column, axis, to_axis_value) {
-    const on_axis = (value) => {
+  function reference_lines(
+    rows: ReferenceLine[],
+    column: "x" | "y",
+    axis: "x" | "y",
+    to_axis_value: (value: string | number) => unknown,
+  ): object[] {
+    const on_axis = (value: string | number | null) => {
       if (value == null) return null;
       const placed = to_axis_value(value);
       return Number.isNaN(placed) ? null : placed;
@@ -94,13 +93,10 @@ const sqlpage_chart = (() => {
     });
   }
 
-  /** @param {HTMLElement} c */
-  function build_sqlpage_chart(c) {
+  function build_sqlpage_chart(c: HTMLElement) {
     const [data_element] = c.getElementsByTagName("data");
     const data = JSON.parse(data_element.textContent);
-    const chartContainer = /** @type {HTMLElement} */ (
-      c.querySelector(".chart")
-    );
+    const chartContainer = c.querySelector(".chart") as HTMLElement;
     chartContainer.innerHTML = "";
     const is_timeseries = !!data.time;
     const chart_type =
@@ -109,11 +105,12 @@ const sqlpage_chart = (() => {
       !!data.stacked && STACKABLE_CHART_TYPES.includes(chart_type);
     const points = data.points.filter(Array.isArray);
     const reference_rows = data.points.filter((row) => !Array.isArray(row));
-    /** @type { Series } */
-    const series_map = new Map();
+    const series_map: Series = new Map();
     for (const [name, old_x, old_y, color, z] of points) {
-      /** @type {ChartSeries} */
-      const point_series = series_map.get(name) ?? { name, data: [] };
+      const point_series: ChartSeries = series_map.get(name) ?? {
+        name,
+        data: [],
+      };
       series_map.set(name, point_series);
       let x = old_x;
       let y = old_y;
@@ -145,7 +142,7 @@ const sqlpage_chart = (() => {
       !!data.horizontal,
     );
 
-    let labels;
+    let labels: (number | string | Date)[] | undefined;
     if (chart_type === "pie") {
       labels = points.map(([name, x, _y]) => x || name);
       series = points.map(([_name, _x, y]) => Number.parseFloat(y));
@@ -297,14 +294,12 @@ const sqlpage_chart = (() => {
       colors,
       series,
     };
-    if (labels) options.labels = labels;
+    if (labels) (options as { labels?: unknown }).labels = labels;
     // Numeric axes count intervals; category and time axes use tickAmount as a
     // target for label density.
-    if (data.xticks) options.xaxis.tickAmount = data.xticks;
-    const chart = new ApexCharts(
-      chartContainer,
-      /** @type {import("apexcharts").ApexOptions} */ (options),
-    );
+    if (data.xticks)
+      (options.xaxis as { tickAmount?: number }).tickAmount = data.xticks;
+    const chart = new ApexCharts(chartContainer, options as ApexOptions);
     chart.render().catch(console.error);
     if (window.charts) window.charts.push(chart);
     else window.charts = [chart];

frontend/src/chart_series.js → frontend/src/chart_series.ts

@@ -1,11 +1,16 @@
-/** @typedef {number|string|Date} XValue */
-/** @typedef { {x:XValue, y:number|string|number[]|null, z?:number, fillColor?:string} } ChartPoint */
-/** @typedef { {name:string, data:ChartPoint[]} } ChartSeries */
-/** @typedef { Map<string, ChartSeries> } Series */
+export type XValue = number | string | Date;
+export type ChartPoint = {
+  x: XValue;
+  y: number | string | number[] | null;
+  z?: number;
+  fillColor?: string;
+};
+export type ChartSeries = { name: string; data: ChartPoint[] };
+export type Series = Map<string, ChartSeries>;
 
 const NUMERIC_X_CHART_TYPES = ["line", "area", "bar", "scatter", "bubble"];
 
-const Y_WHEN_A_SERIES_SKIPS_A_LABEL = {
+const Y_WHEN_A_SERIES_SKIPS_A_LABEL: Record<string, number | null> = {
   bar: 0,
   line: null,
   area: null,
@@ -14,18 +19,18 @@ const Y_WHEN_A_SERIES_SKIPS_A_LABEL = {
   heatmap: null,
 };
 
-/** @param {XValue} x @returns {number|string} equal x values share a key */
-const x_key = (x) => (x instanceof Date ? x.getTime() : x);
+/** equal x values share a key */
+const x_key = (x: XValue): number | string =>
+  x instanceof Date ? x.getTime() : x;
 
-/** @param {ChartSeries[]} series */
-const x_is_text = (series) => typeof series[0]?.data?.[0]?.x === "string";
+const x_is_text = (series: ChartSeries[]) =>
+  typeof series[0]?.data?.[0]?.x === "string";
 
-/** @param {ChartSeries[]} series @param {string} chart_type */
 export function xaxis_type_for(
-  series,
-  chart_type,
-  is_timeseries,
-  is_horizontal,
+  series: ChartSeries[],
+  chart_type: string,
+  is_timeseries: boolean,
+  is_horizontal: boolean,
 ) {
   if (is_timeseries) return "datetime";
   if (x_is_text(series)) return "category";
@@ -38,18 +43,17 @@ export function xaxis_type_for(
 }
 
 /**
- * @param {ChartSeries[]} series
- * @returns {XValue[]} every x the series hold, in their own order where they
- * agree and in ascending order where they diverge
+ * @returns every x the series hold, in their own order where they agree and in
+ * ascending order where they diverge
  */
-export function merged_x_values(series) {
+export function merged_x_values(series: ChartSeries[]): XValue[] {
   const unread = series.map(({ data }) => data.map(({ x }) => x));
   const merged = new Map();
   while (unread.some((xs) => xs.length > 0)) {
     const with_lowest_x = unread
       .filter((xs) => xs.length > 0)
       .reduce((a, b) => (b[0] < a[0] ? b : a));
-    const x = /** @type {XValue} */ (with_lowest_x.shift());
+    const x = with_lowest_x.shift() as XValue;
     merged.set(x_key(x), x);
   }
   return [...merged.values()];
@@ -60,12 +64,13 @@ export function merged_x_values(series) {
  * series that skips an x lands on the wrong one. Give every series the same
  * amount of x values.
  *
- * @param {ChartSeries[]} series
- * @param {number|null} y_when_missing what a series with no value at an x is
- *   worth there: zero to add nothing to a stack, null to leave a gap.
- * @returns {ChartSeries[]}
+ * @param y_when_missing what a series with no value at an x is worth there:
+ *   zero to add nothing to a stack, null to leave a gap.
  */
-export function align_series(series, y_when_missing) {
+export function align_series(
+  series: ChartSeries[],
+  y_when_missing: number | null,
+): ChartSeries[] {
   const all_x = merged_x_values(series);
   return series.map(({ name, data }) => {
     const by_x = new Map(data.map((point) => [x_key(point.x), point]));
@@ -79,13 +84,11 @@ export function align_series(series, y_when_missing) {
   });
 }
 
-/**
- * @param {ChartSeries[]} series
- * @param {string} chart_type
- * @param {boolean} is_stacked
- * @returns {ChartSeries[]}
- */
-export function align_series_for(series, chart_type, is_stacked) {
+export function align_series_for(
+  series: ChartSeries[],
+  chart_type: string,
+  is_stacked: boolean,
+): ChartSeries[] {
   if (is_stacked) return align_series(series, 0);
   if (x_is_text(series) && chart_type in Y_WHEN_A_SERIES_SKIPS_A_LABEL)
     return align_series(series, Y_WHEN_A_SERIES_SKIPS_A_LABEL[chart_type]);

frontend/src/init.js → frontend/src/init.ts

@@ -1,4 +1,4 @@
-export function add_init_fn(f) {
+export function add_init_fn(f: () => void) {
   document.addEventListener("DOMContentLoaded", f);
   document.addEventListener("fragment-loaded", f);
   if (document.readyState !== "loading") setTimeout(f, 0);