5 files changed, 345 insertions, 319 deletions

diff --git a/src/flatmatter.ts b/src/flatmatter.ts
index 4bd141d..f152400 100644
--- a/src/flatmatter.ts
+++ b/src/flatmatter.ts
@@ -1,358 +1,357 @@
-import { trimChar } from "./utils.ts";
+import {trimChar} from "./utils.ts";
 
 export type Matter = {
-  [key: string]: Matter | unknown;
+    [key: string]: Matter | unknown;
 };
 
 export type ConformanceResult = {
-  passed: boolean;
-  error?: string;
+    passed: boolean;
+    error?: string;
 };
 
 export type ParsedValue = {
-  value: unknown;
-  computeActions: ComputeAction[];
+    value: unknown;
+    computeActions: ComputeAction[];
 };
 
 export type ComputeAction = {
-  identifier: string;
-  args: Array<unknown>;
+    identifier: string;
+    args: Array<unknown>;
 };
 
 export interface Serializer {
-  serialize(parsedConfig: Matter): unknown;
+    serialize(parsedConfig: Matter): unknown;
 }
 
 export interface FlatMatterFn {
-  name: string;
+    name: string;
 
-  compute(args: unknown[]): unknown;
+    compute(...args: unknown[]): unknown;
 }
 
 export default class FlatMatter {
-  private content: string;
-  private parsedConfig: Matter = {};
-  private functions: FlatMatterFn[];
+    private content: string;
+    private parsedConfig: Matter = {};
+    private functions: FlatMatterFn[];
+
+    constructor(content: string, functions: FlatMatterFn[] = []) {
+        this.content = content;
+        this.functions = functions;
+        this.parse();
+    }
 
-  constructor(content: string, functions: FlatMatterFn[] = []) {
-    this.content = content;
-    this.functions = functions;
-    this.parse();
+    private parse(): void {
+        for (const line of this.content.split(/\r?\n/)) {
+            this.parseLine(line);
+        }
+    }
 
-    console.log("done");
-  }
+    /**
+     * Parses a given line of FlatMatter.
+     *
+     * @param {string} line
+     * @returns {void}
+     */
+    private parseLine(line: string): void {
+        this.validateLineConformance(line);
 
-  private parse(): void {
-    for (const line of this.content.split(/\r?\n/)) {
-      this.parseLine(line);
-    }
-  }
-
-  /**
-   * Parses a given line of FlatMatter.
-   *
-   * @param {string} line
-   * @returns {void}
-   */
-  private parseLine(line: string): void {
-    this.validateLineConformance(line);
-
-    const keys = line.split(":")[0].trim().split(".");
-    const value = line.split(":").slice(1).join(":").trim();
-    const parsedValue = this.parseValue(value);
-
-    if (!parsedValue) return;
-
-    const config = keys.reduceRight((acc, key) => {
-      return { [key]: acc };
-    }, this.computeValue(parsedValue)) as Matter;
-
-    this.parsedConfig = { ...this.parsedConfig, ...config };
-  }
-
-  private validateLineConformance(line: string): void {}
-
-  private validateLineHasKeyVal(line: string): ConformanceResult {
-    return {
-      passed: true,
-    };
-  }
-
-  private validateLineHasOnlyOneColonChar(line: string): ConformanceResult {
-    return {
-      passed: true,
-    };
-  }
-
-  /**
-   * Detects if the value is a simple value. A simple value is any
-   * of the following: `"a string"`, boolean `true` or `false`, or
-   * anything numeric like `12345` or `123.45`.
-   *
-   * @param {string} value
-   * @returns {boolean}
-   */
-  private isSimpleValue(value: string): boolean {
-    const isString = value.startsWith('"') && value.endsWith('"');
-    const isBoolean = value === "true" || value === "false";
-    const isNumber = !Number.isNaN(value);
-
-    return isString || isBoolean || isNumber;
-  }
-
-  /**
-   * Detects if the value is a function value. A function value is any
-   * of the following:
-   *
-   * - A function call with arguments: `(function-name *args)`
-   * - A function call by reference: `function-name`
-   *
-   * @param {string} value
-   * @returns {boolean}
-   */
-  private isFunctionValue(value: string): boolean {
-    const isFnCall = value.startsWith("(") && value.endsWith(")");
-    const isFnReference = !!value.match(/^([a-zA-Z0-9_-]+)$/);
-
-    return isFnCall || isFnReference;
-  }
-
-  /**
-   * Detects if the value is a piped value. A piped value is a mix of
-   * simple and function value parts, piped together with the forward
-   * slash `/` character. For example:
-   *
-   * ```yaml
-   * posts: (get-content "posts") / (limit 10) / only-published
-   * ```
-   *
-   * or:
-   *
-   *  ```yaml
-   * posts: "posts" / get-content / (limit 10) / only-published
-   * ```
-   *
-   * The result of the previous pipe gets passed to the next as a first
-   * argument.
-   *
-   * @param {string} value
-   * @returns {boolean}
-   */
-  private isPipedValue(value: string): boolean {
-    for (const part of this.composePipedValueParts(value)) {
-      if (!this.isSimpleValue(part) && !this.isFunctionValue(part)) {
-        return false;
-      }
-    }
+        const keys = line.split(":")[0].trim().split(".");
+        const value = line.split(":").slice(1).join(":").trim();
+        const parsedValue = this.parseValue(value);
 
-    return true;
-  }
-
-  /**
-   * Parses a value to a `ParsedValue` object, or `null`
-   * in case it could not for whatever reason.
-   *
-   * @param {string} value
-   * @returns {ParsedValue | null}
-   */
-  private parseValue(value: string): ParsedValue | null {
-    if (this.isSimpleValue(value)) {
-      return {
-        value: this.parseSimpleValue(value),
-        computeActions: [],
-      };
-    }
+        if (!parsedValue) return;
 
-    if (this.isFunctionValue(value)) {
-      return {
-        value: null,
-        computeActions: [this.parseFunctionValue(value)],
-      };
-    }
+        const config = keys.reduceRight((acc, key) => {
+            return {[key]: acc};
+        }, this.computeValue(parsedValue)) as Matter;
 
-    if (this.isPipedValue(value)) {
-      return this.parsePipedValue(value);
+        this.parsedConfig = {...this.parsedConfig, ...config};
     }
 
-    return null;
-  }
-
-  /**
-   * Parses the value part of a line into a simple value, like for example
-   * a `string`, `number` or `boolean`.
-   *
-   * @param {string} value
-   * @returns {string | number | boolean}
-   */
-  private parseSimpleValue(value: string): string | number | boolean {
-    if (value === "true" || value === "false") {
-      return value === "true";
+    private validateLineConformance(line: string): void {
     }
 
-    if (!Number.isNaN(parseFloat(value))) {
-      return parseFloat(value);
+    private validateLineHasKeyVal(line: string): ConformanceResult {
+        return {
+            passed: true,
+        };
     }
 
-    if (!Number.isNaN(parseInt(value))) {
-      return parseInt(value);
+    private validateLineHasOnlyOneColonChar(line: string): ConformanceResult {
+        return {
+            passed: true,
+        };
     }
 
-    return trimChar(value, '"');
-  }
-
-  /**
-   * Parses the value part of a line into a Compute Action, which is
-   * later executed to run the function described in FlatMatter.
-   *
-   * @param {string} value
-   * @returns {ComputeAction}
-   */
-  private parseFunctionValue(value: string): ComputeAction {
-    const isFn = value.startsWith("(") && value.endsWith(")");
-
-    if (!isFn) {
-      return {
-        identifier: value,
-        args: [],
-      };
+    /**
+     * Detects if the value is a simple value. A simple value is any
+     * of the following: `"a string"`, boolean `true` or `false`, or
+     * anything numeric like `12345` or `123.45`.
+     *
+     * @param {string} value
+     * @returns {boolean}
+     */
+    private isSimpleValue(value: string): boolean {
+        const isString = value.startsWith('"') && value.endsWith('"');
+        const isBoolean = value === "true" || value === "false";
+        const isNumber = !isNaN(parseFloat(value));
+
+        return isString || isBoolean || isNumber;
     }
 
-    const fnName = trimChar(value, ["(", ")"]).split(" ")[0].trim();
-    const fnArgs = this.parseFunctionValueArgs(value);
-
-    return {
-      identifier: fnName,
-      args: fnArgs,
-    };
-  }
-
-  /**
-   * Parses the value part of a line into a ParsedValue, which is
-   * composed out of piped parts separated by the forward slash `/` character.
-   *
-   * The ParsedValue will include the default value, if any, and a list of compute
-   * actions which will later be executed.
-   *
-   * @param {string} value
-   * @returns {ParsedValue}
-   */
-  private parsePipedValue(value: string): ParsedValue {
-    const parts = this.composePipedValueParts(value);
-
-    if (this.isSimpleValue(parts[0])) {
-      return {
-        value: this.parseSimpleValue(parts[0]),
-        computeActions: parts.slice(1).map((p) => this.parseFunctionValue(p)),
-      };
+    /**
+     * Detects if the value is a function value. A function value is any
+     * of the following:
+     *
+     * - A function call with arguments: `(function-name *args)`
+     * - A function call by reference: `function-name`
+     *
+     * @param {string} value
+     * @returns {boolean}
+     */
+    private isFunctionValue(value: string): boolean {
+        const isFnCall = value.startsWith("(") && value.endsWith(")");
+        const isFnReference = !!value.match(/^([a-zA-Z0-9_-]+)$/);
+
+        return isFnCall || isFnReference;
     }
 
-    return {
-      value: null,
-      computeActions: parts.map((p) => this.parseFunctionValue(p)),
-    };
-  }
-
-  /**
-   * Takes the entire value part of a line and, assuming it is a function value,
-   * parses it into a list of arguments to be passed down to the function.
-   *
-   * @param {string} value
-   * @returns {unknown[]}
-   */
-  private parseFunctionValueArgs(value: string): unknown[] {
-    const parts = value
-      .substring(1, value.length - 1)
-      .split(" ")
-      .slice(1);
-
-    if (!parts.length) {
-      return [];
+    /**
+     * Detects if the value is a piped value. A piped value is a mix of
+     * simple and function value parts, piped together with the forward
+     * slash `/` character. For example:
+     *
+     * ```yaml
+     * posts: (get-content "posts") / (limit 10) / only-published
+     * ```
+     *
+     * or:
+     *
+     *  ```yaml
+     * posts: "posts" / get-content / (limit 10) / only-published
+     * ```
+     *
+     * The result of the previous pipe gets passed to the next as a first
+     * argument.
+     *
+     * @param {string} value
+     * @returns {boolean}
+     */
+    private isPipedValue(value: string): boolean {
+        for (const part of this.composePipedValueParts(value)) {
+            if (!this.isSimpleValue(part) && !this.isFunctionValue(part)) {
+                return false;
+            }
+        }
+
+        return true;
     }
 
-    const normalizedParts = [parts[0]];
+    /**
+     * Parses a value to a `ParsedValue` object, or `null`
+     * in case it could not for whatever reason.
+     *
+     * @param {string} value
+     * @returns {ParsedValue | null}
+     */
+    private parseValue(value: string): ParsedValue | null {
+        if (this.isSimpleValue(value)) {
+            return {
+                value: this.parseSimpleValue(value),
+                computeActions: [],
+            };
+        }
+
+        if (this.isFunctionValue(value)) {
+            return {
+                value: null,
+                computeActions: [this.parseFunctionValue(value)],
+            };
+        }
+
+        if (this.isPipedValue(value)) {
+            return this.parsePipedValue(value);
+        }
+
+        return null;
+    }
 
-    for (let i = 1; i < parts.length; i++) {
-      const untilCurrent = normalizedParts.join(" ");
-      const quoteCount = untilCurrent.split('"').length - 1;
+    /**
+     * Parses the value part of a line into a simple value, like for example
+     * a `string`, `number` or `boolean`.
+     *
+     * @param {string} value
+     * @returns {string | number | boolean}
+     */
+    private parseSimpleValue(value: string): string | number | boolean {
+        if (value === "true" || value === "false") {
+            return value === "true";
+        }
+
+        if (!Number.isNaN(parseFloat(value))) {
+            return parseFloat(value);
+        }
+
+        if (!Number.isNaN(parseInt(value))) {
+            return parseInt(value);
+        }
+
+        return trimChar(value, '"');
+    }
 
-      if (quoteCount % 2 === 0) {
-        normalizedParts.push(parts[i]);
-        continue;
-      }
+    /**
+     * Parses the value part of a line into a Compute Action, which is
+     * later executed to run the function described in FlatMatter.
+     *
+     * @param {string} value
+     * @returns {ComputeAction}
+     */
+    private parseFunctionValue(value: string): ComputeAction {
+        const isFn = value.startsWith("(") && value.endsWith(")");
+
+        if (!isFn) {
+            return {
+                identifier: value,
+                args: [],
+            };
+        }
+
+        const fnName = trimChar(value, ["(", ")"]).split(" ")[0].trim();
+        const fnArgs = this.parseFunctionValueArgs(value);
+
+        return {
+            identifier: fnName,
+            args: fnArgs,
+        };
+    }
 
-      const lastIndex = normalizedParts.length - 1;
-      const lastPart = normalizedParts[lastIndex];
+    /**
+     * Parses the value part of a line into a ParsedValue, which is
+     * composed out of piped parts separated by the forward slash `/` character.
+     *
+     * The ParsedValue will include the default value, if any, and a list of compute
+     * actions which will later be executed.
+     *
+     * @param {string} value
+     * @returns {ParsedValue}
+     */
+    private parsePipedValue(value: string): ParsedValue {
+        const parts = this.composePipedValueParts(value);
+
+        if (this.isSimpleValue(parts[0])) {
+            return {
+                value: this.parseSimpleValue(parts[0]),
+                computeActions: parts.slice(1).map((p) => this.parseFunctionValue(p)),
+            };
+        }
+
+        return {
+            value: null,
+            computeActions: parts.map((p) => this.parseFunctionValue(p)),
+        };
+    }
 
-      normalizedParts[lastIndex] = `${lastPart} ${parts[i]}`;
+    /**
+     * Takes the entire value part of a line and, assuming it is a function value,
+     * parses it into a list of arguments to be passed down to the function.
+     *
+     * @param {string} value
+     * @returns {unknown[]}
+     */
+    private parseFunctionValueArgs(value: string): unknown[] {
+        const parts = value
+            .substring(1, value.length - 1)
+            .split(" ")
+            .slice(1);
+
+        if (!parts.length) {
+            return [];
+        }
+
+        const normalizedParts = [parts[0]];
+
+        for (let i = 1; i < parts.length; i++) {
+            const untilCurrent = normalizedParts.join(" ");
+            const quoteCount = untilCurrent.split('"').length - 1;
+
+            if (quoteCount % 2 === 0) {
+                normalizedParts.push(parts[i]);
+                continue;
+            }
+
+            const lastIndex = normalizedParts.length - 1;
+            const lastPart = normalizedParts[lastIndex];
+
+            normalizedParts[lastIndex] = `${lastPart} ${parts[i]}`;
+        }
+
+        return normalizedParts.map((part) => this.parseSimpleValue(part));
     }
 
-    return normalizedParts.map((part) => this.parseSimpleValue(part));
-  }
-
-  /**
-   * Takes an entire value of a line and composes it into a list
-   * of piped parts.
-   *
-   * @param {string} value
-   * @returns {string[]}
-   */
-  private composePipedValueParts(value: string): string[] {
-    const parts = value.split(" / ");
-    const normalizedParts = [parts[0]];
-
-    for (let i = 1; i < parts.length; i++) {
-      const untilCurrent = normalizedParts.join(" / ");
-      const quoteCount = untilCurrent.split('"').length - 1;
-
-      if (quoteCount % 2 === 0) {
-        normalizedParts.push(parts[i]);
-        continue;
-      }
-
-      const lastIndex = normalizedParts.length - 1;
-      const lastPart = normalizedParts[lastIndex];
-
-      normalizedParts[lastIndex] = `${lastPart} / ${parts[i]}`;
+    /**
+     * Takes an entire value of a line and composes it into a list
+     * of piped parts.
+     *
+     * @param {string} value
+     * @returns {string[]}
+     */
+    private composePipedValueParts(value: string): string[] {
+        const parts = value.split(" / ");
+        const normalizedParts = [parts[0]];
+
+        for (let i = 1; i < parts.length; i++) {
+            const untilCurrent = normalizedParts.join(" / ");
+            const quoteCount = untilCurrent.split('"').length - 1;
+
+            if (quoteCount % 2 === 0) {
+                normalizedParts.push(parts[i]);
+                continue;
+            }
+
+            const lastIndex = normalizedParts.length - 1;
+            const lastPart = normalizedParts[lastIndex];
+
+            normalizedParts[lastIndex] = `${lastPart} / ${parts[i]}`;
+        }
+
+        return normalizedParts;
     }
 
-    return normalizedParts;
-  }
+    /**
+     * Takes ParsedValue and, optionally an initial value, and runs
+     * compute actions over it to return the final computed value.
+     *
+     * @param {ParsedValue} parsedValue
+     * @returns {unknown}
+     */
+    private computeValue(parsedValue: ParsedValue): unknown {
+        let value = parsedValue.value;
 
-  /**
-   * Takes ParsedValue and, optionally an initial value, and runs
-   * compute actions over it to return the final computed value.
-   *
-   * @param {ParsedValue} parsedValue
-   * @returns {unknown}
-   */
-  private computeValue(parsedValue: ParsedValue): unknown {
-    let value = parsedValue.value;
+        for (const ca of parsedValue.computeActions) {
+            const fnInstance = this.functions.find((f) => f.name === ca.identifier);
 
-    for (const ca of parsedValue.computeActions) {
-      const fnInstance = this.functions.find((f) => f.name === ca.identifier);
+            if (!fnInstance) {
+                continue;
+            }
 
-      if (!fnInstance) {
-        continue;
-      }
+            if (value !== null) {
+                ca.args = [value, ...ca.args];
+            }
 
-      if (value !== null) {
-        ca.args = [value, ...ca.args];
-      }
+            value = fnInstance.compute(...ca.args);
+        }
 
-      value = fnInstance.compute(ca.args);
+        return value;
     }
 
-    return value;
-  }
-
-  /**
-   * Takes a Serializer and uses it to transform internal data
-   * object to a desired output.
-   *
-   * @param {Serializer} serializer
-   * @returns {unknown}
-   */
-  public serialize(serializer: Serializer): unknown {
-    return serializer.serialize(this.parsedConfig);
-  }
+    /**
+     * Takes a Serializer and uses it to transform internal data
+     * object to a desired output.
+     *
+     * @param {Serializer} serializer
+     * @returns {unknown}
+     */
+    public serialize(serializer: Serializer): unknown {
+        return serializer.serialize(this.parsedConfig);
+    }
 }
diff --git a/src/index.ts b/src/index.ts
new file mode 100644
index 0000000..7ac5415
--- /dev/null
+++ b/src/index.ts
@@ -0,0 +1,11 @@
+import FlatMatter, {FlatMatterFn, Serializer} from "./flatmatter.ts";
+import ToObject from "./serializers/to_object.ts";
+import ToJson from "./serializers/to_json.ts";
+
+export {
+    FlatMatter,
+    FlatMatterFn,
+    Serializer,
+    ToObject,
+    ToJson,
+}
\ No newline at end of file
diff --git a/src/serializers/to_json.ts b/src/serializers/to_json.ts
index 9f7b59b..f915a88 100644
--- a/src/serializers/to_json.ts
+++ b/src/serializers/to_json.ts
@@ -1,7 +1,7 @@
-import {Matter, Serializer} from '../flatmatter.ts';
+import type { Matter, Serializer } from "../flatmatter.ts";
 
 export default class ToJson implements Serializer {
-    serialize(parsedConfig: Matter): string {
-        return JSON.stringify(parsedConfig);
-    }
-}
\ No newline at end of file
+  serialize(parsedConfig: Matter): string {
+    return JSON.stringify(parsedConfig);
+  }
+}
diff --git a/src/serializers/to_object.test.ts b/src/serializers/to_object.test.ts
index 98b165a..9f13987 100644
--- a/src/serializers/to_object.test.ts
+++ b/src/serializers/to_object.test.ts
@@ -1,13 +1,12 @@
-import { assertEquals } from "jsr:@std/assert";
-import FlatMatter from "../flatmatter.ts";
+import FlatMatter, {type FlatMatterFn} from "../flatmatter.ts";
 import ToObject from "./to_object.ts";
 
-Deno.test("Single-level configuration", () => {
+test("Single-level configuration", () => {
   const fm = new FlatMatter(
-    'a: true\nb: false\nc: 1\nd: 12.5\nf: "some string"',
+    'a: true\nb: false\nc: 1\nd: 12.5\nf: "some string"'
   );
 
-  assertEquals(fm.serialize(new ToObject()), {
+  expect(fm.serialize(new ToObject())).toStrictEqual({
     a: true,
     b: false,
     c: 1,
@@ -16,12 +15,12 @@ Deno.test("Single-level configuration", () => {
   });
 });
 
-Deno.test("Two-level configuration", () => {
+test("Two-level configuration", () => {
   const fm = new FlatMatter(
-    'a.a: true\nb.b: false\nc.c: 1\nd.d: 12.5\nf.f: "some string"',
+    'a.a: true\nb.b: false\nc.c: 1\nd.d: 12.5\nf.f: "some string"'
   );
 
-  assertEquals(fm.serialize(new ToObject()), {
+  expect(fm.serialize(new ToObject())).toStrictEqual({
     a: {
       a: true,
     },
@@ -39,3 +38,20 @@ Deno.test("Two-level configuration", () => {
     },
   });
 });
+
+test("Simple function usage", () => {
+  class ToUpper implements FlatMatterFn {
+    name = "to-upper";
+
+    compute(input: string): unknown {
+      return input.toUpperCase();
+    }
+  }
+
+  const fm = new FlatMatter('a: (to-upper "value")', [new ToUpper()]);
+  const config = fm.serialize(new ToObject());
+
+  expect(config).toStrictEqual({
+    a: "VALUE",
+  });
+});
diff --git a/src/serializers/to_object.ts b/src/serializers/to_object.ts
index eb21d2f..1b07144 100644
--- a/src/serializers/to_object.ts
+++ b/src/serializers/to_object.ts
@@ -1,7 +1,7 @@
-import {Matter, Serializer} from '../flatmatter.ts';
+import type { Matter, Serializer } from "../flatmatter.ts";
 
 export default class ToObject implements Serializer {
-    serialize(parsedConfig: Matter): Matter {
-        return parsedConfig;
-    }
-}
\ No newline at end of file
+  serialize(parsedConfig: Matter): Matter {
+    return parsedConfig;
+  }
+}