Initial commit

node_modules/@rushstack/ts-command-line/lib/parameters/EnvironmentVariableParser.js

@@ -0,0 +1,51 @@
+"use strict";
+// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
+// See LICENSE in the project root for license information.
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.EnvironmentVariableParser = void 0;
+/**
+ * Some parameter types can receive their values from an environment variable instead of
+ * a command line argument. This class provides some utility methods for parsing environment
+ * variable values.
+ * @internal
+ */
+class EnvironmentVariableParser {
+    static parseAsList(envVarName) {
+        const environmentValue = process.env[envVarName];
+        if (environmentValue !== undefined) {
+            // NOTE: If the environment variable is defined as an empty string,
+            // here we will accept the empty string as our value.  (For number/flag we don't do that.)
+            if (environmentValue.trimLeft()[0] === '[') {
+                // Specifying multiple items in an environment variable is a somewhat rare case.  But environment
+                // variables are actually a pretty reliable way for a tool to avoid shell escaping problems
+                // when spawning another tool.  For this case, we need a reliable way to pass an array of strings
+                // that could contain any character.  For example, if we simply used ";" as the list delimiter,
+                // then what to do if a string contains that character?  We'd need to design an escaping mechanism.
+                // Since JSON is simple and standard and can escape every possible string, it's a better option
+                // than a custom delimiter.
+                try {
+                    const parsedJson = JSON.parse(environmentValue);
+                    if (!Array.isArray(parsedJson) ||
+                        !parsedJson.every((x) => typeof x === 'string' || typeof x === 'boolean' || typeof x === 'number')) {
+                        throw new Error(`The ${environmentValue} environment variable value must be a JSON ` +
+                            ` array containing only strings, numbers, and booleans.`);
+                    }
+                    return parsedJson.map((x) => x.toString());
+                }
+                catch (ex) {
+                    throw new Error(`The ${environmentValue} environment variable value looks like a JSON array` +
+                        ` but failed to parse: ` +
+                        ex.message);
+                }
+            }
+            else {
+                // As a shorthand, a single value may be specified without JSON encoding, as long as it does not
+                // start with the "[" character.
+                return [environmentValue];
+            }
+        }
+        return undefined;
+    }
+}
+exports.EnvironmentVariableParser = EnvironmentVariableParser;
+//# sourceMappingURL=EnvironmentVariableParser.js.map