Merge pull request #2 from eugene-matvejev/v1

init commit. proof of concept

Author: eugene-matvejev

index.js

@@ -0,0 +1,12 @@
+'use strict';
+
+let fs = require('fs'),
+    packageJsonPath = `${process.cwd()}/package.json`,
+    packageJsonContent = fs.readFileSync(packageJsonPath),
+/** @param {{extra: {node_parameter_handler: []}}} content */
+    packageJson = JSON.parse(packageJsonContent),
+    Processor = require('./src/processor'),
+    processor = new Processor(packageJson.extra.node_parameter_handler, process.cwd());
+
+processor.process();
+processor.write();

package.json

@@ -0,0 +1,26 @@
+{
+    "name": "node.js-parameter-handler",
+    "version": "0.1.0",
+    "description": "build .json files which can be used as settings",
+    "main": "index.js",
+    "scripts": {
+        "test": "in progress"
+    },
+    "repository": {
+        "type": "git",
+        "url": "git+https://github.com/explore-node-js/node.js-parameter-handler.git"
+    },
+    "keywords": [
+        "config handler, parameter handler"
+    ],
+    "author": "Eugene Matvejev <eugene.matvejev@gmail.com>",
+    "license": "MIT",
+    "bugs": {
+        "url": "https://github.com/explore-node-js/node.js-parameter-handler/issues"
+    },
+    "homepage": "https://github.com/explore-node-js/node.js-parameter-handler#readme",
+    "dependencies": {
+        "deepmerge": "^1.3.1",
+        "jsonfile": "^2.4.0"
+    }
+}

src/file.js

@@ -0,0 +1,2 @@
+module.exports = class File {
+}

src/processor.js

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+let fs = require('fs'),
+    deepmerge = require('deepmerge'),
+    File = require('./file');
+
+module.exports = class Processor {
+    constructor(config, cwd) {
+        this.config = config;
+        this.cwd = cwd;
+    }
+
+    process() {
+        this.files = [];
+
+        this.config.forEach(config => {
+            let file = this.processFile(config);
+
+            this.files.push(file);
+        })
+    }
+
+    write() {
+        this.files.forEach(file => fs.writeFile(file.output, JSON.stringify(file.content, null, 2), 'UTF-8'));
+    }
+
+    /**
+     * @param {{envMap: {}, output: string, source: string}} config
+     *
+     * @returns {*}
+     */
+    processFile(config) {
+        let file = new File();
+
+        let pathSource = this.resolvePath(config.source),
+            pathOutput = this.resolvePath(config.output);
+
+        let packageJsonPath = this.resolvePath(pathSource),
+            packageJsonContent = fs.readFileSync(packageJsonPath);
+
+        /** @param {{extra: {}}} content */
+        let packageJson = JSON.parse(packageJsonContent),
+            solvedJson = this.resolveOverwritten(config.envMap),
+            completedJson = this.constructor.getMergedData(packageJson, solvedJson);
+
+        file.source = pathSource;
+        file.output = pathOutput;
+        file.content = completedJson;
+
+        return file;
+    }
+
+    /**
+     * @param {string} path
+     */
+    resolvePath(path) {
+        if ('/' === path.charAt(0)) {
+            return path;
+        }
+
+        return `${this.cwd}/${path}`;
+    }
+
+    resolveOverwritten(envMapping) {
+        let object = {};
+
+        for (let abstractPath of Object.keys(envMapping)) {
+            let envVariable = envMapping[abstractPath],
+                value = this.constructor.getEnvironmentValue(envVariable);
+
+            this.constructor.overwriteObjectFieldValue(abstractPath, value, object)
+        }
+
+        return object;
+    }
+
+    static getEnvironmentValue(index) {
+        return process.env[index] || undefined;
+    }
+
+    static getMergedData(data, overwrittenData) {
+        return deepmerge(data, overwrittenData);
+    }
+
+    static overwriteObjectFieldValue(abstractPath, value, object, delimiter) {
+        if (undefined === value) {
+            return;
+        }
+
+        delimiter = undefined !== delimiter ? delimiter : '.';
+
+        let indexes = abstractPath.split(delimiter),
+            lastPartIndex = indexes.length - 1;
+
+        for (let i = 0; i <= lastPartIndex; i++) {
+            let index = indexes[i];
+
+            if (i === lastPartIndex) {
+                object[index] = value;
+                break;
+            }
+
+            if (undefined === object[index]) {
+                object[index] = {};
+            }
+
+            object = object[index];
+        }
+    }
+};

tests/fixtures/package.json

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+{
+    "extra": {
+        "node_parameter_handler": [
+            {
+                "source": "tests/fixtures/settings.json.dist",
+                "output": "var/settings.json",
+                "envMap": {
+                    "touched": "BASE_URL",
+                    "test.touched": "PWD",
+                    "test.test.touched": "HOME"
+                }
+            }
+        ]
+    }
+}

tests/fixtures/settings.json.dist

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+{
+    "touched": "to be replaced",
+    "untouched": "untouched",
+    "test": {
+        "touched": "to be replaced",
+        "untouched": "untouched",
+        "test": {
+            "touched": "to be replaced",
+            "untouched": "untouched"
+        }
+    }
+}